The fact that there's the sound of two people having sex in the bathroom, shamelessly at that, is enough to draw Roxas's attention away from whatever else is going on. He still kind of has to go, which he takes to the urinal and deals with, but he can't help but fixate on what's going on in the stall so close to them.

Don't blame him. He's young, these things are exceptionally distracting for him. Hormones. Some other excuse.

When he's finished it isn't a surprise what Shin has done. A shame, maybe, but he knows he can't do anything to stop it. As long as things don't get crazy.. like it might be getting given the sounds coming from that stall.

Are they freaking filming in there?

Figuring that no one and nothing is listening to him other than Shin, "Does this sort of thing happen often in here?"