Peter could say something smart, but is too scared and dumbfounded to open his mouth.
He had accompanied Mr. Stark and The Avengers to a fight against Doom, who had lost his marbles again. Maybe Peter should give him a bag to keep them in?
..... Okay, that had sounded funnier in his head. On with the story.
Peter had half-accidentally tampered with something important, and it exploded. He was sucked into a wormhole, and now he was stuck in a Bizarro Universe.
Peter Parker ends up in a mirror universe where heroes are villains and vice versa.