Peter rolls his eyes but he doesn't argue but he doesn't promise anything, either. It's not a lie if he doesn't promise anything. Maybe.

"Do you think if we did go back home, that you would go to the future since you remembered stuff and I'd go back to that crashing plane? That'd suck. I mean, the Tony back home wouldn't be you, you know? You'd be in the future, doing future stuff with a different me."