That's actually one of the only ways to introduce Bones/Booth romance that I think I'd like. Its adorkable and low key and they'd better not f it up.
I can just see it:
Booth: Bones, I'm not going to live halfway across the city from my child. Its too hard enough with Parker. We'll have to get an apartment together.
Bones: Its perfectly natural that after living with Booth for a while, I should develop sexual feeling for him. Its just because I'm forced to be aware of his body in new ways. If I ignore it, it'll go away once I get used to this new change in our relationsihp.
Baby: I'm so cute and adorable, wee!
Booth: You're too tense Bones. Let me get you some coffee, give you a footrub, and do various endearingly sweet things.
Bones: Just...keep...ignoring....it....
Angela/Cam/various strangers: You two are adora.....er, I'll be going now
Bones: Booth, I've come to the conclusion that it makes the most sense if we were to engage in physical intimacy so as to help create a stable home environment for our child.