Peter would love you sticking your hand in his back pocket,
you’d walk up while he was talking with the squad and just slide your hand into his pocket making him freeze and look at you, who had a very cheeky grin on your face "What? all that running gives you a really nice ass" and give him a squeeze noting the extremely bright blush it got out of him.
it soon became a regular thing, instead of holding hands you’d slide your hand in his pocket with a grin and usually a comment on his firm butt

credit to @quiskcilver ❤ for the idea!