It's hard to pick a "worst" since most of the time it's a one night stand for a reason, but I'd have to say it was when I was in Germany. I met this girl at the club who was hanging out with my friends and I all night. We end up back at our house and this girls gets into a screaming fight with another girl we're with. My friends decide I have to get rid of her. She doesn't speak a word of English and I didn't speak a word of German beyond sorry and Jack Daniels. We end up traveling about 45 min away to her house before she gets me to stay. It's now about 11 am since we've been partying all night I figured, why not. After we finally pass out her husband shows up with their kid screaming at the door (no idea about what) and trying to get in. She motions to me to climb out the window and leave.

Either that or the time I was so drunk outside of a bar smoking a cigarette when a woman approached me asking for a light. Not even five minutes later we were in a cab to her place. Woke up the next morning to a woman who had to be 30 years older than me smoking crack and telling me I had to go since her first appointment of the day was coming over. I didn't ask what services she'd be providing but I definitely got tested after that one.

Oh, can't forget the girl who puked all over my brand new (literally less than 3 days old) couch. Fortunately the warranty covered it and they came to steam clean it a few days later. Still didn't sit in that spot for months after.

A couple of bonus ones....

When I still lived at home with my mom my "friend" and I decided to do it in the stairwell since my mom was one room over. Getting home drunk apparently we were loud and my mom thought it would be funny to lock us out....naked. Had to get the keys from the doorman wearing nothing but a smile.

Once my mom woke up at 5 am to a very drunk naked woman who had just thrown up all over her living room rug. She was cool about it, I cleaned up and she loves to tell the story at gatherings.