Regardless of the situation, sex changes things. Getting it in can affect even the most casual acquaintances, so check out these common sexual encounters and make sure you know what you’re doing before you do it.

1. Same-sex experience

Not getting any action Downtown? If you’re out with a good friend and you’re both drunk enough, there’s nothing wrong with a little experimenting. It’s good practice, and who knows, you might like it. You can often find girls making out with each other on the dance floor at bars. Sometimes the most mature people are the ones who aren’t afraid to get a little weird with a friend. After a night of homo-erotica, things can be a little awkward, but the best way to handle the situation is to acknowledge it. Laugh it off with your pal over breakfast the next morning. A real friend won’t take the experience too seriously.

2. One-night stands

Whether you just met someone Downtown or ran into a friend from a former class, one-night stands can be tricky. Once you return from sleeping elsewhere — and complete the obvious walk of shame — the best way to handle a one-nighter is to forget it happened. Act cool if you have a run-in at any point, and joke about the night with your friends. At any other point in life, stumbling home without your phone in some random vomit-covered sweatshirt would be considered disgusting. In college, it’s acceptable.

3. Walking in on your roommate

During our 18 pre-college years, some of us have walked in on our parents. It happens. And when it does, it’s usually somewhere unexpected like your bed or the backyard trampoline. So when you get to college, there’s a good chance you’ll walk in on your roommate having sex, especially since roommates are generally more active than our parents. If you (or your roommate) walk in at the wrong time, the best thing to do is just say sorry and forget about the whole thing. If you’re feeling especially Hammurabi-esque, you can even ask a girl or guy over when your roommate is around so the awkward moment can be mutual. In all seriousness, there’s nothing to do when you walk in on your roommate except forget about it.

4. Sleeping with a friend’s ex

Maybe you had too much to drink. Maybe the whole thing was a mistake. Maybe you’re just a bad person. For whatever reason, you did your friend’s ex. You’re probably going to hell. Hooking up with a good friend’s ex can be totally fine — even rounding a few bases isn’t the worst thing on earth. But you let thing go a little too far, so now what are you going to do? If the friend in question is one of your best, it may be good to just tell him or her. If word gets back and you didn’t tell him or her first, there might be a fight.