Mirror in bathroom.
Also aside from that, there's this horrible bug with saves in the game, for some reason past a point if you ever roll back with the mousewheel, it just goes back to this one save I made on wensday with marge in the living room after I tried the game on the phone, same thing with trying to load a save past a certain point. It's really annoying since anytime I want to rollback text it just shoves me back to that point and then I have to get the job at the kwikie mart AGAIN after waiting a day and listen to skinner scold me for the bathroom again. Restarting the game doesn't help either.
Edit: Ok, I went past the marge handjob scene and it suddenly fixed itself, maybe it has something to do with that
Edit 2:Ok, it's back again, it doesn't like rolling back during scenes it seems and doesn't fix itself after the scene either, roll back is REALLY glitchy in this game it seems