It isn't a surprise to see her anger, since he's impressed she kept that in long enough to hand him a drink without throwing it at him. The way the side of his face aches is enough for him to gauge how much she didn't appreciate his reappearance. Honestly, if he'd been thinking straight at all, he would have known when to spare her from even going to her party. Obviously he hadn't been.

Still, it seems to have some effect on him. Now he's realizing that she isn't kicking him out, and more that it's awkward to have this conversation while she's towering over him. Delaying his answer further, he takes some time to rock forward, using his arm as a brace and works himself up to stand. Only far enough to collapse back down in the nearby chair to hold his head again, but at least he's off of her floor.

"It's a long story." How many times has he said that, for it to keep getting longer? She could probably tell him. "...But if you really want to hear it, you might want to get some coffee."