Colin Farrell, Matthew Davis and Clifton Collins Jr in Tigerland (2000)
In this movie, Colin Farrell appears fully naked and Matthew Davis only shows us his butt. But he has incredible abs, so we forgive him! In that scene, they are having sex with girls im the same bedroom. No foursome, just sharing the same bedroom. Colin's penis view is very brief as he walks in front of the camera.
31 minutes in the movie, Clifton Collins Jr drops his pants in front of his unit. He as a long shirt, so we can't see much. Only his dick head, cut, appears below the shirt.