Bruce slides into the bed beside Zerxus without a single word or explanation, rolls onto his side and effectively manhandles the mortal into his arms and curls around him.

The desperation Zerxus has to be touched is obvious. Bruce being fundamentally lonely is (Bruce thinks) less so. His motivation for 'keeping an eye on' Zerxus damn well better not be obvious, to anyone.

That there is any concern beyond the man 'trying something stupid' and a desire to.... acclimate him is not a thing Bruce will look at directly.

Once he is even remotely settled, the lights just go away.