From the perspective of a "gay label" guy who has had an ongoing sexual relationship with three married men, I would like to make a comment.
I have never wanted to have sex with anyone - male or female - who was cheating, ie. their partner was unaware of the situation. It is very important to me that anyone wanting an open relationship with their spouse or committed partner should have thoroughly discussed this extra-relationship with the partner and got their free knowledge and agreement.
If you are using the word "cheating" more loosely to mean extra-marital sexual relationships that a wife or girlfriend knows about and agrees then I have no concern.
One was a fellow doctor in the hospital in which i worked. His wife fancied me, too, and she knew that her husband and i were having sex a couple of times a week. She was envious that she couldn't have a similar sexual relationship with me but she agreed that her husband and I could be sexual. It ended when he moved away to be a GP and distance relationship was unfeasible.
Another was the husband of a female doctor colleague, They were close friends of mine. We acknowledged and discussed that prior to their marriage, I fancied him, he fancied her and she fancied me. Before they became a couple, she and I had sex together but we stopped as there wasn't really a future to that aspect of our friendship. Later, when they had been married for three years, he decided that he didn't see sexual orientation in a categorical sense and wanted to explore his curiosity of having sex with men. The 3 of us discussed it and he and I had an intermittent sexual relationship for 4 years. It ended when he had sex with several women without discussing it with his wife and they decided to divorce. His 2nd wife did not want him to have sex with me. Additionally, they also divorced because he had sex with other women without her knowledge and agreement.
The third was a bisexual (mainly gay) doctor, who had married a bisexual woman so they could conform to their respective family's heterosexual expectations. There was no problem about him being my partner because she had a female partner.
A once-off "almost" extra-marital episode occurred. I became friendly with a quantum physicist and we developed a bromantic relationship. He would say, "If I were gay, i would love to have you as my boyfriend.". When he got married, he and his wife stayed with me on their wedding night on the way to their honeymoon holiday. When I gave them coffee in bed the next morning, she encouraged me to get in bed with them because I was getting cold sitting in my underwear talking to them. She urged her husband to explore his sexual boundaries. We 3 kissed and cuddled. All 3 of us got turned on. She and i masturbated each other for a short time and she put his hand on my cock and I held his cock. After a few strokes, he felt anxious and I left them to it to have sex together while I had a shower, dressed and made breakfast.
I expect honesty and trust and consideration of each other's feelings in any close relationship. Some people choose monogamy. Others may choose to have an open relationship. Any change in the relationship regarding extra-marital relationships should, in my opinion, be discussed openly, and sensitively. Similarly, if a couple agree to extra lovers then each new relationship should be discussed and only begin if the spouse or partner knows and agrees to it taking place.
If anyone chooses to cheat then they would be advised to be able to handle any possible consequences which may occur.