It was a large old house that five of us - roommates - were living in. We were at the very end of a 2 year rental agreement and 4 of us had already found new places to live, and were spending that last month going back and forth between that house and our new places, moving furniture, etc.

The 5th person was a guy that we allowed to move in a few months before that; he took over a room someone else had already left, and was supposed to leave when we did, according to the lease. Important note: this guy and I had dated for a very short period of time well before he moved in, but we were on good enough terms and both were dating other people when he moved in as a roommate.

In the last week or so, he was really the only one still at the house. The rest of us had mostly moved out and cleaned the place up. Unbeknownst to us, he used this as an opportunity to invite a bunch of his "friends" (who were apparently local crackheads) to crash in the house, along with his girlfriend (who fucking HATED me, for no reason other than he and I had briefly dated before). They spent the entire week TRASHING the place - punching holes in the walls, removing all of the light switch covers (?), breaking windows, etc. His girlfriend also went outside, removed bags of trash from the cans out back, and scattered the trash all over the room that bad been mine. For some reason, human feces was found on top of some of the cabinets, and there were syringes and baggies of drugs found scattered around the living room, where it also looked like they had found a bunch of mattresses on local tree lawns and brought them inside so the crackheads had places to sleep.

This was all discovered because me and another roommate showed up on the last night of the lease to make sure everything was good for the landlord the next day, and we interrupted another one of their drug-fueled parties. We freaked out and left, landlord showed up around midnight (I think just to check the place out), and the guy and his shitty girlfriend and their awful friends scurried away when they saw him and left him with the mess.

We felt awful about it. We knew that his girlfriend sucked - she had a shitty attitude from the moment he first started bringing her around, and tbh she came off as trashy - but this guy was like a normal enough dude, office job, a little flighty but overall seemed okay. We did NOT think that he would end up completely trashing the place like that.