Because even though they feel the need to seek physical intimacy from someone else, they still want the stability and safety a relationship brings.

Cause I'm single and trying to pass this math test

Because you need to be brave. Cheaters are cowards.

Remember that Beyonce song about the guy who cheated on her, but it's cool because she wasn't that into him and the other guy she's been seeing is on his way over to replace him?

Sometimes everybody sucks at being in a relationship.

People aren't honest enough with each other and their own needs. Meanwhile we build other dependencies in long term relationships that have nothing to do with physical attraction, but are in most cases more important for all kinds of reasons.

Monogamy is the basis of a lot of unnecessary suffering because it's resisting a very real need we continue to have even when our relationships become romantically stagnant. If we could all just be honest about it with our SOs without fear, and work together as we do anyway to maintain other commitments to each other, we could have a culture where there's a lot more freedom to seek more intimacy and love in a way that isn't dishonest, that isn't "cheating".

Its not the most sensitive info here, but you shouldn't censor things using non-opaque markings. It's pretty trivial to throw the image in an editor, crank up the brightness, and see what's behind the censor in this case. Just wanna let you know in case you happen to do this to some sensitive info

Why not just have two relationships?

Cheating is for young people and mentally ill adults who haven't fixed their impulse control

Adulting requires making partner and family the priority if you signed for it.

Someone should have told my exwife this handy life hack. Would have saved me untold grief and depression. However, life can throw you a beautiful little surprise after a nightmare. If it wasn't for that godawful woman, I never would have met the love of my life, the woman who I spent my whole life waiting for and now enjoying what it means to be happily married to my biggest crush, my best friend and waking up right next to her and our little family every morning. I can safely say it was all worth it. It could have been easier to get here but I'd do it again on legendary difficulty if I had to.

I have an baseless theory that people that first has sexual experience when they were young or in strict households and had to sneak around and hide their relationships are more likely to want to chest because the "thrill" of hiding the relationship and tabbooness of it reminds them of their formative sexaul experiences.

Because being adult in age isn't at all the same thing as being adult in maturity plus often people derive different benefits in different kinds of relationships so they want to keep both going (for example, somebody in his or her 40s happilly married with kids and yet getting excitement and sexual pleasure with a younger lover).

Also there are often huge social and financial implications to breaking up certain types of relationships or under certain conditions, but people might still be irresistibly drawn to something else, so they play a game to both sides not wanting the costs nor willing to run the risk of losing one to get the other.

It's a mix of selfishness, immaturity, cowardice and people changing over time and discovering that the stable relationship they're in doesn't fit them (either anymore or they get to a point were they figure out it never trully did)

Yeah, I never understood it either. Either have an open relationship with consent, or communicate whatever needs you have that you want to fulfill by cheating properly, and accept that it may not work out if there is truly no way to meet them. I guess I can at least abstractly understand when it happens spur-of-the moment and under the influence of drugs/alcohol, but I still can't properly put myself in those shoes.

Because the government pays you to be married