I love everyone in the comments acting like he should "read the room" and talking about how "obvious" her mood and movements are, when they're missing the clear obvious fact that these two are ALREADY EXTREMELY CLOSE.

It's likely this is her boyfriend already, and she's being pissy, potentially because he fucked up, and he's just trying to make up for it with a kiss or by being "nice" and she's not having it.

This is not what people look like when strangers are all up on them, and this is not the type of environment for strangers to be up on you like that. They are at a small gathering not some large party and she looks pretty unphased by him literally pressed up against her.