Well this was a... touch awkward.
Truth be told? Jason kinda thought birthday parties were a bit... dumb. Or... well, no, that wasn't the word. Unnecessary? No, that's not it either. ...He doesn't ask for one himself and he doesn't feel too bad if he doesn't get one, is the point he's going for here, but that doesn't mean somebody else can't have a birthday party, y'know? And if he gets invited to one, well, yeah, he's gonna try and show up. It's what you do. If somebody likes you enough to invite you, of course you try and show the heck up. Duh.
He never figured he of all people would be the only friggin' one to think that way about it apparently? Since when is he the one most likely to honor the expected social contract? What the heck. He knows you invited, like, everybody. The whole Family, couple'a Kents, even... the gang, as it were. So where was everyone?
It doesn't help that he's late. Not, like, super-late? Like half an hour. Not long enough to believe the others had swung by and just gone home already. Long enough that he can imagine you sitting there thinking nobody was coming for way longer than he's comfortable with. Crap.
Still, awkward and uncomfortable and - honestly, a bit angry on your behalf? - as he's feeling right now, Jason does his best to look chill and put on a grin. 'Cause let's be honest, you're probably already feeling a bit cruddy, he doesn't get to go piling on top of that by being all pitying right now. Nobody wants that.
"Hey, kiddo. Sorry I'm late. There was some trouble down at the Docks I had to straighten out, y'know how it goes. Gotham, am I right?" He hopes he doesn't sound like he's trying too hard. Probably does. Oh well. Look, Dick's the one who's good at the Big Brother Energy, okay? Jason's trying.