Do you leave your washcloth and towel for him to use too? How bout your shavers? Shaving cream? Do you put asshats on your toilets too?
What about drinks in the fridge? He might be leaving lipstick marks on them when he swigs directly out of the bottle.
Do you have a face towel close to the toilet?
How bout your toothbrush? Toothpaste? Maybe he rubs his nasty toothbrush right up against the spout of your toothpaste? Mouthwash bottle? Cup?
Oh so many possibilities of you two swapping your nastiness together without even knowing it.