does he drink? does he not bother to turn the light on in the dark cause he thinks his aim is that good? there are a lot of variables, but missing the toilet and not cleaning up after ones self is just plain laziness. and like you said, unsanitary. maybe he thinks his bathroom, he wont have to hear you complain about stepping in it anymore and on with the gross mess. my ex partner, now roommate is a daily drinker, in the dark pee-er, there is a small night light in there, but if he notices a mistake its cleaned immediately, even the porcelain under the ring gets a wipe between full cleanings. maybe a full on talk is necessary?