Relationships are great, but there are just some people you should never date. Ever.

Your Friend's Sibling

Sure, your bestie may have a cute older brother, and how great would it be if you were sisters in law, but it's not going to work out that way. Sure it worked for Monica and Chandler, but that's TV. If you guys break up, it could really hurt the relationship between you and your bff. I once dated a friend's cousin. That was a little different because they didn't live in the same house but it was still a little awkward when he came over to visit after he and I broke up. Not a good feeling. Her and I still remained friends, but I don't think our friendship was the same after that.

The Ex

There used to be a code about these things, but apparently that's gone out the window, so I'm here to tell you that you can't date your friend's ex. Someone is going to get hurt and it's probably going to be your friend. I once dated someone who was friends with an ex of mine. I didn't know they were living together so, imagine my surprise when I'm making cereal in my Spongebobs and my ex walks out into the kitchen. Even if you ask your friend and they say it's OK, just don't do it.

The Married Set

This should be a no brainer, but I still feel like I need to put it out there. They aren't going to leave their spouse for you. It's just not going to happen, so stop asking. Most people who cheat are just looking for the goods and a relationship based on just that is never going to last. I once got involved with a guy who said he was getting divorced. Turns out he was still very much married with two adorable children. His whole world collapsed after she found out and I kicked him to the curb. Lots of drama and hurt feelings that weren't worth it.

Your Co-Worker

A lot of people think this one is OK because "No one's going to find out" and "We can keep a secret" and "Who cares? If we break up, I can always find another job". Many companies have policies that prohibit dating a coworker. I did it and we were able to hide it, but, when we split, I wasn't all that upset about it, but I think it was awful for him because I dated again right away and he got fired.

The Boss

This one never, ever, ever, ever, ever works out ever. Ever. It's not a good idea because if your coworkers find out, they'll retaliate, especially if you get promoted over someone else who felt like they deserved it and you'll probably end up alienating the whole office and no one wants that. If you're truly attracted to your boss, it's best to find another job before the whole place finds out.