Babylon
Michael finds Brian on the catwalk and cuts short the hand job he's receiving. He asks where Justin is, and Brian says he's at home doing a "project". Whose name happens to be Ethan, who we are, disturbingly, cutting to all through this scene.
Michael's trying to rouse up some suspicion in Brian so that he doesn't have to spell it out... saying that he called, that Justin didn't pick up. Brian admits that he knows what Justin is doing when he's not there. He says Justin is 19, and why should it bother him if Justin wants to have some fun?
And what if there was someone else?
Brian responds that Justin doesn't owe him anything....but don't they at least owe each other honesty? I don't think Brian's being at all honest either. Whatever he says, knowing there is someone else bothers him a LOT more than he lets on here. When it's just sex, he doesn't care. When there's an actual attachment, it moves into cheating—they are supposed to be emotionally monogamous, if not sexually.