So I've got this roommate who is a pretty big prick. He has treated myself along with my other roommate like shit pretty much the entire semester and doesn't really seem to care. He has admitted to eating some of my food in the beginning of the semester but I constantly notice more food missing and I know my other roommate isn't doing it because we hang out most of the time and when he wants some of my food, he asks.
Not only that, but I'm pretty sure he's been using my soap also. Everytime I go in the shower, there is less and less of my soap, and a lot of the time there are pubes on my soap... and I know they're not mine.
Anyways, so I've confronted him about both things, and he just gets SUPER defensive and starts to yell at me about it. My mom suggested putting exlax in some of my food, but I'm not sure if she was joking about it. I'd like some ideas on how to get him to stop before I end up killing him.