Open relationship here. The trouble with them is they require a level of trust, open communication, and honesty about feels that a lot of people aren’t willing to do. Partners need to be able to discuss feelings of jealousy when they happen. You have to trust your partner and trust the others you engage with. Then there’s navigating the stigma of it. I’m engaged with a man married to a woman (they’re also open and she’s absolutely on board with this). As their kids get older, he’s having to decide if he can keep it going or if he is too worried how his kids would handle finding out about it. Most open relationships are kept very secret, and living any kind of secret life is exhausting.