The problem, theoretically, was that at first, he'd gone to the wrong room.
The other problem, theoretically, judging from what looked like the very baby start of a black eye, was that he'd gotten into a thoroughly wretched fight with Astrid, who was supposed to be his date, just like he'd told Tony –
Well, anyway, he was here. As per invite. And his replacement date was, in theory, going to show up soon, too.
Which was why, instead of greeting anyone who was supposed to be there, the first thing he did was – very irresponsibly! – jump on his brother's back without warning, giving him a noogie.
It was only after he'd jumped back down, cackling quietly, that he offered Tony a grin in greeting.