Bruce says not a single word, just puts one hand on Zerxus arm, slides down to his wrist and puts his hand against the wall. Then repeats the motion with the other hand. Implicit instruction: lean into the wall and don't fall.

He brushes a kiss across Zerxus' neck, from behind.

Then simply gets the soap and gets busy determiedly removing sweat, grime, and blood from Zerxus' skin. He does the back and hair first, then presses against Zerxus' back and does the same for his front.

As far down as he can reach, anyway. On his knees to complete the job is too obviously an act of service, instead of a sexual tease and taking advantage of an exhausted man.