That moment of hesitation tells him a lot more than Ianto probably realises about the fact that he obviously still mostly bottoms for Spike and nothing's changed there, and there's a flicker of a grin as he hands over the lube. He's sure that, whatever hasn't changed in Ianto's relationship with Spike, Ianto still knows his way intimately round an ass with lube and that he has nothing to worry about there.

He brings his knees up a bit to give Ianto room and the right angle to work, and then wraps his arms around him again, groaning into his mouth as those achingly familiar fingers begin to work their way inside him.

It's... been a while since he's felt a man's fingers inside him, and he's really glad it's Ianto who gets to renew that experience for him.