I snagged some caps from a cam version of the movie, they aren't great, but I didn't see Mewe's dick once, you do see his nuts at the end. I might have an edited version where were the frontal shots at in the movie?
It was near the end when Zack came back to talk to Miri and win her back -- they had just finished talking through the bathroom door when Mewes walks out of the bedroom butt-ass nekkid.