I'm pretty sure you have one of...those friends. You know, the one that just doesn't know when to leave you alone. And by "won't leave you alone" I'm saying "they're pretty much hunting you down just to be with you."
Clingy, yes?
And no matter how obvious you make it that you don't want them around without actually saying "I don't want you around," they still stay there and yap and yap and yap...
For instance, you're sitting in lunch, next to your friend that you genuinely want to be with, and your CLINGY friend is sitting there with you too because one of the fates decided to be particularly sinister one day and makes your lunch schedule and her lunch schedule the same. So you're having a conversation with your good friend, making all sorts of inside jokes and references that completely go over the clingy friend's head.
Good friend: I got thick eyebrows 'cause I don't want things falling out of my forehead!
Clingy friend: Wait, what?
NiGHTS: *waves hand over head* Peeow! ("over your head")
Clingy friend: *defensive* No, I didn't hear what he said!
Good friend: *sigh* *repeats himself*
Clingy friend: ...OH! LOL!
NiGHTS: ... ... ... *waves hand over head* Peeow!
Not like I'm a mind reader or anything, but I knew she had no idea what we're talking about because she barely even knows what anime is, much less FLCL, and even more less the obscure eyebrows reference that only those who have watched and understand FLCL would get. I mean, I know the statement is pretty funny, even without the reference, but it's even funnier for someone who does get it.
...
I dunno where I was going with this...
But anyway, the point is, it really frustrates me when someone tries to force themselves into the tightly-knit relationship that's already developed between two people. You can't force a friendship to begin with.