The face that he has been yearning for it is very much the point. In fact, it is the only point. It's the point because it means he's easy to distract, and because it means Bruce doesn't need to acknowledge how much he uses sex to meet... needs that are certainly not physical.

Hell, (pun intended), Bruce doesn't even have to consciously realize he does so.

He keeps the kiss deep and slow, but his fingers gradually curl tighter and there's the slightest hint of teeth. Interestingly there's nothing harsh about it, and the warmth doesn't fade at all. There's just more steadily building intensity.

And Bruce pushing... against Zerxus more than into him. Not quite 'telling' him to get onto his back or demanding it, but seeing what Zerxus does with the pressure.