1. You’ll be tempted to have sex whenever you hang out.

Since sex is especially awesome with someone whose body you know inside and out, banging an ex can be super convenient and satisfying. Ex sex is a shortcut to a high-quality orgasm, but it’s only advisable if you can rely on your former partner to swing by for a one-night-stand and then promptly excuse himself or herself from your life until the next time you’re alone and horny and not really in the mood to jerk off. If your ex wants to be your fuck buddy until you land yourself an upgrade, fine. But if you choose to classify your ex as an actual friend, you’ll find yourself tempted to engage in a convenient grade-A boning session whenever you hang out and you can’t fuck and buck a friend because that’s just rude.

2. Your established boundaries won’t hold up.

Boundaries are for keeping dogs from running into the street and for keeping people from acting unprofessional in the workplace and for keeping children from falling down stairs. They aren’t for friendships. Friendships are supposed to foster freedom. We call on friends for support, to listen to us vent, or to let us gossip without judging us for being shitheads. We show our friends the scariest, deepest, darkest corners of ourselves. Since it’s tough to stay friends with an ex without inching back towards coupledom, a lot of lovers-turned-friends resort to establishing ground rules (e.g. “let’s just not talk about so and so,” or “let’s only hang out during the day so we don’t get drunk and stupid together,” or “let’s only communicate every other Wednesday”), but boundaries are suffocating. True friendship transcends the rules we live by when interacting with everyone else. Who wants a friend they can’t get tipsy with or call up on a Monday? No one.

3. You’ll waste time getting back together.

If you’re hanging out with your ex-turned-friend, you’re bound to have some good times together because that’s what friends do. The problem with good times is that they have a way of clouding all the shit that led you to break up in the first place. Every time you share a good laugh or a good cry during a sad movie you will take one step closer to trying, in vain, to reboot the relationship. Things might seem early stage lovey-dovey for a bit, but the bad stuff will reemerge—and you’re probably just as incapable of resolving issues as you were the first time you decided to part ways. Back and forth relationships are exhausting. Really. Why bother?

4. You’ll cock-block each other.

The only people silly enough to attempt friendship with an ex are the people secretly interested in winning them back. Most of us have tried and failed to stay friends with an ex at some point, so we all know that the lingering presence of a former boyfriend or girlfriend in someone’s life is a sign that things aren’t quite over yet. No one wants to get involved in an already complicated situation when they can just log on to Tindr. So the second you admit to being good friends with your ex, you might as well kiss that potential replacement mate bye-bye.

5. You’ll alienate everyone you date.

If, by the grace of Eros, you find yourself a new partner who’s willing to overlook the fact that you’re still friends with an ex, your new mate’s chill attitude won’t last. There’s a point in most relationships when people stop making the exceptions that define the early stages of dating because we can’t remain blindly in lust or love forever. As time goes by, every underlying issue manages to bubble to the surface, and there’s nothing like a “friend” you once fucked and/or loved to piss off your significant other, who will surely demand that you make a choice between this irksome “friend” and them. It’s tough to blame a man or woman for feeling threatened by a person’s inability to make a clean break with a former partner. We all want heartfelt commitment, which generally means leaving the vaginas you once occupied and penises you once blew behind.

6. You’ll bore your actual friends.

Breaking up sucks whether you’re the dumper or the dumpee. During such difficult times, we rely on our core group of outside-the-fuck-zone friends to comfort and distract us. But there’s a cap in everyone’s tolerance level for listening to people mourn the end of a specific relationship. When you try to keep your ex in your life as a friend, you end up annoying the fuck out of your real friends who will eventually tire of trying to keep track of whether or not you’re together or want to be together. Remember, no one likes hearing the same sob story more than once or twice.

7. Your digital presence will confuse people.

If you count your ex a friend, you can’t delete all the old coupley photos of you two from your social media accounts, or untag yourself from the photos in their feeds, which might be construed as dickish. That means that your digital presence is going to confuse all the people who thought you were now single and available. These people will question whether or not you’ve really moved on since you can’t seem to let go of all those cheestastic photos, and they definitely won’t feel as comfortable asking you out as they would if you’d buried the digital remains of your relationship properly.

8. You’ll make each other jealous.

Our exes still have the power to make us jealous. No one wants to see someone they once dated being hit on by another man or woman, let alone reciprocate the flirtation. So unless you’re both ugly and unlovable, you’re bound to piss each other off whenever either one of you is propositioned. Possessed by the green monster, you will likely say and/or do stupid things that you will later regret.

9. You’ll become a problem cyberstalker.

Cyberstalking can be a healthy practice, but not when born from raging jealousy rather than pure curiosity. When you hear that your ex is seeing or hooking up with someone new—information that travels through friend circles as quickly as pulp-less orange juice through a colander—it will be difficult to restrain yourself from launching a thorough online investigation. It’s too easy to get sucked into the rabbit hole of Googling your ex to death, which may or may not lead to reasonable conclusions about their real life actions, but will definitely lead to you driving yourself more than a little bit mad. Why not spare your own sanity?

10. You’ll feel awkward introducing each other.

When you try to stay friends with an ex, you’re bound to encounter situations that demand introducing them to other people. But how do you refer to this person when you unexpectedly bump into your old college buddy or your mom’s Pilates instructor? You can’t call them your “former boyfriend/girlfriend” because that sounds cold. And the simple “this is ______” seems unnecessarily cagey. But calling them a “friend” won’t feel right either because your energy as a twosome will say otherwise. Plus, you might offend your former flame with the downgrade in title and blaring reminder that the relationship is definitely over. There’s no proper way to introduce someone you once loved who now resides in friend territory, so why put yourself in the awkward position of having to try? Human interaction is taxing enough as it is.