Redskins Asst. Coach Pees In Gatorade Cup On Sideline

NFL Fans in Detroit got more than they bargained for on Sunday when they saw a Redskins coach whip out his penis and urinate into a Gatorade cup on the sideline ... DURING the game!

The urinator is Washington's special teams coordinator Ben Kotwica -- who tried to sneak over behind a trash can and relieve himself during the 3rd quarter of the game.

Problem is ... the pee break went down right in front of a bunch of Lions fans who ALL saw the whole thing. The person who snapped these pics was at the game with her two minor kids.

One of the people in the group says Kotwica was the 2ND coach to expose himself and pee by that trash can during the game.

We reached out to the Redskins and a rep had no comment -- however, one team source tells us sideline pee breaks happen "all the time" with players and coaches and they always try their best to be discreet.