Few topics are more contentious in the world of consensual non-monogamy than that of the One Penis Policy, or OPP. Broadly speaking, this refers to a situation wherein a cisgender male/female couple open up their relationship, and the man insists that his wife or girlfriend is allowed to date other women… but no men.

You might be surprised to know that this is extraordinarily common. Men see it as a way to reduce or eliminate jealousy in a newly-open relationship. This might even seem reasonable on the surface. But when you scratch a little deeper, there’s a lot of toxicity at play in the OPP. Here’s five great reasons you want to avoid it.

It’s a double standard

The men I’ve heard argue in favor of the OPP are typically the partners of bisexual women. They argue that their partner can date women, which fulfills the “other side” of her sexuality. (The assumption being that she gets all her male needs met by him.) These men might even say “I can date women, she can date women. She can’t date men and I don’t want to date men. It’s even!” But if you believe this, you’re deluding yourself. Assuming you identify as a straight man, you’re not giving anything up by not dating other men – you wouldn’t want to anyway! But if your partner identifies as a straight or bisexual woman, she probably would like to date men.

It’s a double standard. And that almost never leads anywhere good.

It’s homophobic

There’s a real double-whammy at play here.

First, the OPP as a means of combatting men’s jealousy is homophobic because it implies that relationships between women are less “real.” Think about it – if a man is threatened by his partner being with other men but not being with other women, this is probably because he believes (even if not consciously) that sex between women is not “real sex” or that relationships between two women can never be as meaningful as a relationship between a woman or a man.

The other side of this is that men who institute an OPP in their relationships often do so out of a desire for threesomes or at least being able to “watch” their partner’s experiences with women. Some even insist upon this as a condition for their partner to be allowed to date. This reduces relationships between gay and bisexual women to entertainment for the benefit of men – live action lesbian porn, if you will – which is a classic trope of biphobia and a specific intersection of misogyny and homophobia.

It’s trans-exclusionary

The OPP is inherently rooted in cis-sexist ideas about gender. It assumes that all men have penises, all women have vulvas, and there are no other gender options in between or outside of this binary.

Proponents of OPP are often stumped when you ask them what would happen if their partner wanted to date a transgender woman with a penis, or a trans man with a vulva. The answer varies somewhat, but it usually boils down to them saying their partner can date a person of any gender identity as long as they have a vulva.

This implies that you don’t see transgender people as their real gender, and believe that the complex nature of gender can be reduced to simply what’s between someone’s legs.

It reduces sex, relationships and your self-image to one single body part

If you sit down with a man who advocates for OPP and ask him what he’s really afraid of, it usually comes down to “I’m afraid someone else’s penis can pleasure her better than I can.” (Or sometimes, “What if he’s bigger than me?”)

Dude, my dick is probably bigger than yours. It’s also made of silicone and has purple sparkles! And it doesn’t matter! You’ve woefully misunderstood sex, female pleasure, and the nature of relationships if you think your penis alone (or anyone else’s) can make or break things.

Penis-in-vagina intercourse is great for many people, but it’s far from the be-all, end-all of sex. There’s also hand sex and oral sex and toys and kink and just… so many different things.

Your penis isn’t what makes you YOU, and your penis isn’t why your partner loves you. Stop reducing the amazing, complex and dynamic human being that you are down to just your dick.

It sets the stage for resentment

I’ve known so many women who have agreed to an OPP to keep their partner happy, telling the world – and themselves, sometimes – “I don’t want any other men anyway, he’s all the man I need!”

Great, except… there’s no need to legislate against something you don’t want anyway. Almost inevitably, it comes out eventually that actually these women would quite like to date men and are chafing under their partner’s restrictions. Eventually, if not addressed, this leads to resentment. And once it’s embedded, resentment can be hard to kick and can be toxic to a relationship.

So if you’re not going to do OPP, what can you do instead? The truth is, you can’t eliminate jealousy entirely – it’s a natural human emotion. What you can do is learn tools to mitigate and manage it. But honest communication, vulnerability and openness with each other, and a system in which the same rules apply equally to both of you is by far the preferable option to the toxicity that is the One Penis Policy.