He wrinkles his nose. "You're not the first to tell me that. Matt said something similar-- not sure I really want to know the details, since I can't do anything about it. Apart from pre-emptively apologize, maybe."

Peter and Matt have had their fair share of differences in the past, but if Luke's noticed the same change at the same time, it's not an isolated disagreement. Which leaves Peter with a problem he has no way of solving, because even when he does get home again (please let it be when), he won't remember any of these conversations.