Billy's face goes bright red in shame and annoyance...at Theo, at himself, at the entire situation.
Well, how the hell am I supposed to know what's going on? Just because we're alternate-reality versions of each other from what we know, doesn't mean everyone is. It's not like I do this every day!
Images of the last few, hectic months pop into his head...the team being founded by a time-travelling teenage version of one of the Avengers' worst enemies. An intergalactic war brewing on their doorstep over the man he loves. Every superhero in America taking sides in a Civil War over their very human rights. Shape-shifting alien invaders, other-dimensional armies of destruction...
OK, maybe I do. But that doesn't mean I know how to deal with it!
What Billy refuses to admit, even to himself, is that despite everything he's done, and everything he can do, he's still not even 17 yet. Being a superhero means growing up fast...just ask Spider-Man. But it's one thing to deal with adult problems, quite another to deal with dimensional crashes that result in everyone you know turning into a total stranger.
As he climbs down from the tree, Billy stays behind it, more out of humiliation than fear.