As the Master unbuttons his shirt, the Doctor does the same with his--less quickly, though, clumsier, as he is not looking at what he's doing, his eyes still on the Master. He gets rid of shirt, undershirt and socks, but is still wearing his jeans when the Master tosses aside his socks and straightens up to look at him.

The Doctor, instead of unbuttoning his trousers, steps up to the Master and takes his face into his hands, his thumbs on the other man's cheekbones, the fingers of his right hand brushing over the red bite mark on the Master's neck. He keeps this position only for a short moment--giving the Master no time to react, which he would, if the Doctor let him; the gesture oversteps quite a few boundaries, lines in the sand drawn a long, long time ago--before he pulls the other man into a kiss, his hands traveling down over the Master's chest around his waist underneath the waistband of his boxers. He pushes them out of the way, unceremoniously, and cups the Master's ass in his palms, squeezing not-too-gently as he presses his hips against the Master's.

Then he breaks the kiss and steps back, trying to keep his breathing level. "Lie down. On your stomach."