From your post two weeks ago, the pair worn by Duncan Black are the Rugby Lace Up Athlete Jock, by Timoteo.
My butt in a c-in2 white Jockstrap
Canadian fan submitted underwear images
CASANOVA blue side-split shorts.
Thursday Aussiebum bulge briefs.
What are you wearing today?
Open-ass AC Yellow jock-brief
Do you wear these? When and Where?