[Jack always has liked a bit of fight just as much as tender love, if not more. He can feel the inherent strength in Spike's grip on the back of his head, and in the lean body pressed up against his, and it feels fucking incredible. He loves making love to Ianto, and even more so now he's got him back from the dead, but Ianto doesn't have this fight to him (or at least, he fights back in different ways) and fuck, but he's missed this. Missed the violence and danger – things he'd been seeking out more and more frequently in the months between Ianto's death and winding up here – and the sheer turn-on of that clash of wills and bodies.
He pushes into the kiss, one hand instinctively behind Spike's head to protect it from being scraped against the wall, his other curled around a leather-clad bicep, as he shunts his hips forward, partly to keep Spike pinned against the wall, and partly – instinctively – to get some pressure on his rapidly hardening cock.]