Jack definitely had his share of fun that night and being reminded of that now means he's just starting to realise himself what else might be got out of a three-way blue band contract, other than just being able to fuck Ianto again. It makes it even harder to cool down in the face of being thwarted by the damn wardens, but if Spike can manage it, so can he.
He grits his teeth and scoops up his dropped shirt and wraps it round his bloodied arm as he'd originally intended, though it's mostly stopped bleeding anyway now.
"I'm sorry," he says, turning his glare up at the sky into a rueful smile for Spike. "That really wasn't meant as a taunt of what you can't have."