<human>: Let me first of all acknowledge that this is a really silly and petty predicament, but I want to see if there's a resolution. Anyway, I'm living in a two-person apartment with three other people (Steve, Mary, and Lisa). We're all 2nd-year college kids. 

It's been OK until recently, when Mary started bringing home some random old guy who looked mildly homeless. Whatever. I leave for winter break for a few weeks, and when I get back, I notice that this guy (Joe) doesn't leave. He spends every night here, eats all his meals here, and fucks Mary constantly (sometimes very loudly when me/Lisa/Steve have guests over). They've also been very messy in the past, although they did improve a bit when I warned them about it.

Lisa is friends with the owner of the unit, so the solution seems obvious, right? Tell Joe fuck off, and if he and Mary object, just threaten to let the owner know what's going on. Here's the issue. Me and Steve like to throw parties, and we're not supposed to do that per the terms of the contract (and our personal agreement with the owner). Should I tell Mary to stop, she'll probably just appeal to that clause in the contract and say that we're "misbehaving" as well. On top of that, we're underage, and they could probably call the cops on us if they wanted.

I don't really want to sacrifice the right to party, but I want this guy out. Is there a solution, or do I need to put up with it? I'd rather not resort to anything petty or childish, but I'd consider most things since none of us considers Mary a friend anymore.

Give me a shortened version of the text
<bot>: Roommate's deadbeat boyfriend moved in, and the only apparent way to get rid of him is to sacrifice the right to party, which I don't want to do.