PS: I just realized that if we're having them meet up in the bath, obviously they're both either going to be nude or scantily clad (I mean, varyingly depending on how far down in the water the first one in is) so: I guess also, "really defining features" includes super noticable scars, tattoos, ...idk, nonhuman anatomy.

If he's already in the bath, there's less moving around to observe, though, unless he's splashy :P Or we can have them both get out of the changing rooms at the same time, too, and have a moment of Oh. Well, okay.