Of course, there are people who follows ethical non-monogamy. But when I was single and meeting people, I talked with my single friends and it was common to find certain profile of men who had a wife or a girlfriend but told you that they were single. They wanted a “fling”, so basically they didn’t care if women broke up with them when they find out. In fact, that seemed to be something good for them, because they didn’t wanted commitment and that way, they didn’t need to break up themselves.

The best way to identify or discard those people was to change the day of the date. If they offered a wednesday, you say “sorry, I can’t. But friday is good”. Or something on those lines. Single people have it easier to change schedules, cheaters don’t. XD

Non monogamous and Polyamory are good in my book because they tell you upfront. Then is up to you to decide if you want that kind of relationship. And it is not cheat if everyone is in the same page.

But the cheaters are a completely different thing. Besides, if they don’t respect their current partner, why are they going to respect you?