There are countless movies that start off with the idea of “friends with benefits,” but you know how all those movies end? With those former friends turned buddies falling in love and presumably living happily ever after. Why? Because once you start reaping sexual benefits, you’re no longer just friends.

1. Friends don’t have sex.

They just don’t. Isn’t the word platonic somewhere within the definition of a friendship? Friendships between two people of the opposite sex should be just as non-interesting as friendships between people of the same sex. You’re friends. You can’t be sex buddies, because at the end of the day if you’re really friends then you both care.

2. If you’re really “just friends” then there’s no sexual attraction.

That would be way too complicated. Friends are the people you don’t sleep with. The ones who have always been there because you’ve never had any sort of romantic or sexual drama. That’s why you’ve stayed friends — because sex and friendship just don’t mix. You can sleep with anyone — with stakes that high, why would you ever sleep with a friend?

3. When it comes to sex, love will always get in the way.

You can try for meaningless sex, but other than a one-night stand, sex will always wind up meaning something. If you’re friends then you already have an emotional connection. Adding sex makes you just one more step closer to love. There really is no other way.

4. Is there room for jealousy?

You’re sleeping with your friend, but another man catches your eye — is your friend okay if you start benefiting from this other man too? No? Then it should be pretty obvious that you’re not just friends. Once you start caring about each other’s sex lives, being just friends will never be an option again.

5. Your future partner will never see them you guys as “just friends.”

Someday you’ll find “The One,” and what will he think of this little arrangement? Will he be cool when you still hang out or will your sexual history with each other bother him? You’ll either end up together or you’ll lose each other forever. Is sex really worth all that?

6. What’s the difference between friends with benefits and a boyfriend?

Let’s see, you sleep with both and you talk to each of them about your day, feelings or whatever you want to discuss. A friend is someone who’s always there for you. A boyfriend is that too — and oh yeah, he also has sex with you. So please, explain the difference one more time at least.

7. You can never go back to being “just friends.”

Once you cross that line, you can’t uncross it. You can’t go from friends to lovers and back again. You’ve seen each other naked and now your “friendship” will never be platonic. What happens when this little arrangement ends? You either fall in love then marry each other or your friendship is over forever — you can’t have it both ways.