They've certainly been involved in their fair share of Quidditch-related scuffles, but this is somehow new and different in a really not good way.
Well, Harry thinks as Malfoy's knee accidentally rubs against him just there, maybe it's a little bit good. No, wait, it's Malfoy; definitely completely bad.
Harry shoves at Malfoy again, trying to push their bodies apart, but their limbs are so tangled that all Harry really accomplishes is writhing against him.
He hopes to Merlin it's the violence that's turning him on. Weird as that would be, the alternative that it's Malfoy makes his brain explode.