The difference between ethical non-monogamy and cheating, according to a therapist

• In monogamous relationships, a range of intimate interactions with other people could be considered cheating.
• This can lead to confusion about ethically non-monogamous relationships, where someone has multiple partners but isn't cheating.

People in monogamous relationships can't seem to agree on what "cheating" entails: A kiss with a stranger? A drunken one-night stand? Exchanging flirty texts with a colleague?

But for people in ethically non-monogamous relationships, there's a clear line between faithfulness and infidelity, and it has nothing to do with whether or not other parties are involved.

It all comes down to breaching a partner's trust, Rachel Wright, a sex and relationship therapist who is also in a non-monogamous relationship, told Insider. (Wright uses the term "non-monogamy" without the modifier "ethical" because it suggests relationship setups outside of monogamy are inherently unethical, which isn't the case, she said.)

"Cheating is cheating, because cheating is going against an agreement," Wright said.

She said there's no specific sex acts that make up "cheating." Rather, it's what partners agree to uphold together.

That means people in any relationship dynamic, whether non-monogamous or monogamous, can cheat on their partners. In both relationship styles, cheating is characterized by a lack of communication and breaking of trust, according to Wright.

Define 'cheating' with your partner using as much detail as possible

Society teaches us to avoid conversations about relationships and sex, but getting into the nitty gritty can help you better understand the difference between cheating and non-monogamy, Wright said.

"There are all of these gray areas because we're humans," she said, so having an honest and in-depth discussion about what feels good for you and your partner is the best way to define "cheating."

"They just assume that everyone's having the same experience, and there's some relationship rule book that everybody's going by. We all know, logically, that's not true," Wright said.

People in non-monogamous arrangements have more options for their sexual and romantic lives than people in monogamous relationships, which means they over-communicate their expectations and boundaries often.

She gave the example of two people in a polyamorous relationship. They may agree to date outside of their primary relationship, but also set a rule that they don't invite their prospective partners back to their shared home. If one partner broke that rule, that would be cheating, Wright said.

But if that partner had sex with an outside partner somewhere other than their home, it wouldn't be cheating.

"Really, the biggest difference is that someone is not 'in the know.' Someone is being blindsided," Wright said.

To get a better understanding of what "cheating" means to you, Wright suggested examining your personal relationship with jealousy.

When a person feels jealous, it often signals insecurity, Chapman University psychology professor and relationships researcher Amy Moors previously told Insider.

Rather than create relationship rules that prevent jealousy, it's healthier to understand how you can care for yourself when that emotion comes up, Wright said.