The press of a hard cock is something Jack very much enjoys too, all the promise of it, the physical evidence of want that this time will not be denied. It's good to feel Spike's against him too, even if it's gone all too soon when Spike kneels up. He gets Spike's tight ass against his own boner, though, so it's all good.
His breath leaves him again when Spike pulls off his shirt, the expanse of pale skin not new to his sight but new to his ability to touch it. He's still wearing way too many clothes for this himself - greatcoat and all - but he'll get to that in time. For now, he's too engaged groaning again at that roll of Spike's hips (for someone so recently bisexual, he certainly knows just how to tease a guy!) and reaching to grab him, snarling out, "You'd better fucking following through this time!" before pulling him into another clashing, crashing, breathless kiss.