This is poorly formatted and is likely to have spelling/grammatical errors, and I just wrote down everything that popped into my head. I am not a writer, nor am I very logical. I am a huge fan reaching and over-analyzing.
I was watching s4 last night and it got me thinking. It's been very well established that 7th eps are CB, and it seems very much like 18th eps are DB. Now, we don't necessarily always get things that are obviously good for that couple on those eps, but underneath the surface there is something positive. CB examples: 2.7>CB schemes, Chuck starts to kind of get interested in Vanessa, Blair gets jealous and ruins it, Chuck gets really mad at her and basically tells her that she can forget him sleeping with her until she says "I love you" (ugh). So, on the surface it isn't that great, they end the episode mad at each other, and I personally think it was also the test run of CV to see if audiences would be accepting of it or not, but further down you got to see Blair being very threatened and jealous of Vanessa, and it established that while the face they are showing to their friends is just sexual tension and whatnot, they actually both are interested in more than just that but are afraid of what happens next (aka the writers ott convoluted reasons to keep them apart for a whole freaking season). Another CB example is 5.7. Superficially it was about her not trusting him and his need to feed her delusions, but what we are supposed to get from that, not that I do, is that the idea of Chuck being actually good scares Blair because of what it means about her, her relationship with Louis, and her past with Chuck. From Chuck's side we see that he recognizes that and that he is kissing her to make her think he is still evil so she wont want him because he actually loves her, (Wow, when you type it out like that, it is a lot more dumb than I first thought.) and I actually think it was also laying the foundation of Chuck's all-consuming magnetic selfish love vs Dan's innocent, altruistic, selfless love. Ok, done talking about CB for the moment, going to delve into DB in a moment. So overall, the 7th episodes on the surface appear to do one thing, but underneath they start to put a lot of other things into play.
DB's 18th ep thing is actually a lot more interesting to me because it is so consistent and before they ever got together. DS do not have anything like this (I went through all of the ones I could think and didn't see any kind of pattern), NB don't, SN don't, and really SB don't (though I guess you could say they have a moment every season finale, but that rarely has any heart and it always feels more like a year in review) So the only two pairings that do are CB and DB, and this seems to really be where the writers are heading for kind of the "final showdown" or whatnot. (I have more thoughts on this that I will spew forth later if you guys don't kill me first.)
So each 18th has had some meaningful DB scenes and usually are a way of charting Dan's character growth. 1.18: He realizes that maybe scheming can be used for something good, so he turns to the other person who cares as much about Serena as he does (that parallels 4.10 nicely too). Blair compliments his abilities and starts the tradition of these two being the only ones who can pull of schemes that don't backfire, let's not get started on how bad things happen once Serena or Chuck is brought in.
2.18: Dan learns that as much as he wants to escape this world, this world is now part of who he is and will affect all aspects of his life. His relationship with Miss Carr was a way for him to avoid dealing with Serena and the drama of Rufly getting together, and that ended with someone he viewed as being outside of the crazy of the UES ended up scheming against Blair. He feels sorry for the way his drama has effected others, he told Rachel all those things about Blair and Serena because he didn't want to have to actually work through that drama and pain, and she used that knowledge against them, and as a result, apologizes to Serena about causing a rift between SB, and he gives Blair information that she can use against him if she wants, which she could have used to get him expelled, but chooses not to.
3.18: Dan's ice melts. Eleanor asks him to do something, which in season 1 he would have straight up ignored and gotten defensive about, but he recognizes that she is at least somewhat fond of him, she laughs and smiles and jokes with him, something we dont see Eleanor do with "the help" in the same episode where she was being very WASP-y in her treatment of Dorota and Vanya, and she also asks him about his gf, before asking him to do something. If she viewed him as below her, she wouldn't have shown any kind of interest in him, she would have just told him to do it or she would have been the one to make the cater waiter joke, not him. He recognizes that she isn't being superior, she's being friendly. Season 1 Dan would not have made this distinction and would have jumped to the conclusion she was insulting him and would have gone on a judgemental bender. He doesn't though, he laughingly agrees and goes to do it. Another marker of his progress.
Then we have the DB scene. After doing something season 1 Dan would never do, he comes across forlorn Blair. You see in his face that he doesn't want to stop and try to figure out what's wrong, but one thing that has never changed about Dan is his willingness in trying to help people. He stops and talks to her. He recognizes that her attitude is somehow related to Chuck, and he seems very protective of her when asking about it. Dan puts on this face of disliking her, but he has seen Blair at her most emotionally weak points, 1.4, 2.8, and knows that she can be very vulnerable.He also knows that Chuck preys on vulnerability. (This comes up again with 3.22 and the whole "You, tell her" line) He then goes on to try to reassure her that she and Chuck belong together because he thinks that's what she wants to hear, much like 5.10. He also goes out of his way to tell her that he doesn't think she is a bad person. Then she mentions his ice is melting, and it's such a great line because it works on so many levels. Literally, the ice he is carrying is melting, but more importantly his ice towards the UES and her in particular is melting. He really sees what she thinks of herself, and it's obvious that he is not ok with that.
We also see that he realizes that maybe he gave her bad advice regarding herself and her connection with Chuck. We then have Blair publically announcing, for the first time I think, that she isn't happy, that Chuck no longer makes her happy. and then later, Dan comes over, tries to protect her by standing in front of Chuck and his hussy. and declares she deserves to be with someone who makes her happy, asks her to dance to distract her, and later is doing shots with her and her parents, ensuring she is surrounded by people who love her unconditionally, interestingly enough, he is part of that group, not Serena or Nate. In this episode, he has finally accepted that he is part of this UES world, the conversation with Eleanor, and that maybe, not everyone and everything is horrible and maybe they are just as broken as everyone else, his first convo with Blair, and that there are also good things as long as you are willing to step outside of you bubble and look around, his convo w/ B about happiness and then later the shots with family and the GG line about being suprised by the people
already in your life.
4.18: This is the most interesting to me because for the first time, this one is the first one that feels more like the way they do the CB 7th eps, minus the melodrama. It has a lot of surface stuff, but it also has a lot of stuff that is deeper and applies to how DB view each other, themselves, and each other in regards to themselves. If 1.18, 2.18. and 3.18 had a lot about how Dan was growing to accept this world and with B being the poster child for it, it makes sense that those milestones for him would be marked in regards to his interactions with and concerning her, but 4.18 shifted slightly, and it was no longer just about Dan's view on the UES and B in particular, but also hers about him. I mean I think there elements of that in the other 3 episodes too, but this is really the one that laid the foundation for the current DB arc and what I would like to think, is to come.
In 4.18 we have Dan who, even before he misread signs and thought she wanted him, was completely smitten. It was funny how obvious it was, but he refused to at all even pretend like it was possible until Eric says something, and even after that, he never vocalizes having feelings for her. He then misreads signs and thinks Blair is scheming, and like Eric said, he usually would be bothered by that, but because of his liking Blair, he's not. This is kind of his final acceptance of UES, the last marker in his character growth in re: to that world. He is willing to go get an expensive nice suit, even Blair commented on how good it looked, willingly go along with a scheme that involves him being part of something that glorifies wealth, grandeur, and power because he has feelings for someone. He would never ever in a million years have done that for Serena. Look at what it took to get him at Cotillion and that was really not much more than an expensive school dance.
We also have Blair's weird behaviour this episode: spending a week in bed following an epiphany that the person she wanted was the person she always wanted? Even for this show, that's kind of pushing it. It is not until after she comes across Vanessa, and they have their little feud, do we actually see Blair mentioning that Chuck is the one. Up until that point, she had been fairly calm about everything, argues with Vanessa who represents so much baggage, that we see her start acting weird. She tells Dorota to bring her clothes to the event, we see her acting like a robot when she is talking about Chuck being her destiny. Never do we see her say she wants to be with Chuck because she wants to or because he makes her happy, it's all about fate. She doesn't see anything outside of the planned future. Which says that either she did feel something during that kiss, and her conversation with Vanessa reminded her how many issues there would be in following that unknown road, so she shoves all those feelings down deep until she later transfers them to Louis aka not Chuck, or she desperately wanted to feel something during that kiss, didn't, and resigns herself to her "fate"
She and Dan have a convo, she learns that he came there because he thought she wanted him there, but because she has resorted to her world of oblivion, she doesn't put two and two together about what this means re: his feelings, likely because Chuck is there looming like a creeper in the night. The conflic with Chuck starts and she immediately defends Dan. She doesn't ask about him trying to humiliate her or win her over or whatnot, her first thought goes to him trying to hurt Dan, and that was all it took for her to turn her back on her so-called epiphany and say she was done with him. She was looking for the first out and she took it. She also answers for Dan in that scene re: the kiss. She doesn't really give him a chance to tell her that he did feel something. She says she felt nothing, looks to him for affirmation and he gives it. She left no opening for him to say otherwise, further supporting the idea that she had felt something and pushed it so far down.
They then go out and have their second private conversation. She says she didn't do it regarding the scheme and he says that he knows. This always stands out to me. She needs him to know that she wouldn't do something like that to him, and he lets her know that he trusts her. That is really big considering DS and CB. With DS, he was always concerned about what Serena was doing, what kind of drama she was dragging him into, what kind of world she belonged to, and in CB, Chuck mentioned so many times how he didn't trust her. Those were really the cracks in the foundation of those relationships, and yet DB were able to just breakout of that. He trusts her and she makes sure he know she is being honest and telling him the truth, at least the part she is willing to admit to herself.
He then confirms the kiss means nothing and she looks dejected. Everything about that scene says that is not what she wanted to hear, but once again, she really didn't give him an opening. He had just been humiliated, told that their kiss made her want her ass-y ex, and that it had meant nothing. There was no reason for him to think that being honest would do anything but cause more pain to himself and upset her. This also sets up in her mind, that he has no feelings for her. She sees this as time he could have been honest with her, she had rebuffed Chuck in front of him, no one else was around; therefore he had no reason to lie. This is the moment that cements he feels nothing in her mind, and even if there was some confusion as to why not, she sees Serena step into the picture and it becomes clear. In her mind, Serena is his fate, like Chuck is hers. He might not be chasing her now, but eventually he will, and with all of B's insecurities especially regarding Serena, she would never see the moment when Dan of all people, would want her truly and fully. She thinks that even if he were to want her now, the moment S came back into the pic, it would be like s1 NS all over again. This is the scene that makes it completely believable that she has no idea about his feelings in s5.
She says something about his princess being ready for him if he is and sadly walks away. He looks to see what he means and we don't see happiness or relief. We just see hurt and some slight annoyance. He does not see his love life being fated like Blair does with her own. This, imo, is the moment where he really realizes that for the first time, in a very long time, he truly has no interest in Serena anymore. He is ready for his princess, she just doesn't want him.
It really sets up what we have seen so far in s5, and what I think we are likely to see. Dan having major insecurity issues regarding Chuck and Blair obviously with Serena. They both think that the other would never truly be interested, and so feelings are either projected, Louis, or ignored, at least Dan tries to up until 5.8. DB will be more complicated than just a CBD triangle or a SDB triangle because both of them are coming similar places with similar histories of being hurt and strung a long. Neither of them will act first because they are too afraid of the result.