aha, uncles normally topless or singlet la, but mostly like my dad, wears briefs, even to sleep!
sometimes they wear semi-mesh fabric ler, kinda hard not to notice the underwear line... those who didn't wear any i can see their butt crack... plus, i can ask them if they're wearing 
we're pretty open minded in the house, that's why we don't really mind if the guys are being topless or walk around with towel
haha loose huh?
oh, to be fair, i wear bra all the time besides in the bathroom and sleep (and depends who's with me,  )... sometimes at home i wear those training bra style... more comfy. feels 'easier' being supported, don't guys feel the same with penis?