Monogamy is a (lifestyle choice) not a DNA code.
There is no need to renounce it because it's not mandatory. No one has to enter into an "exclusive relationship" or (make promises) to anyone to only have sex with one person.
We live in an era where there are lots of "hookup dating sites", "open marriages", "booty calls", "friends with benefits", and the classic "one night stand" or "vacation sex" opportunities. There are also escort and gigolo services available to those willing to spend money on sex.
With so many sexual opportunities out there cheating should be obsolete! One can easily find someone who wants what they do!
Cheating is about "breaking the rules", secrecy, deception, lying directly or by omission, making false promises, and betrayal.
The goal of most cheaters is to (hold onto) all that is "good" in their primary relationship while addressing their other "needs" on the side. The vast majority of cheaters aren't looking to replace one relationship with another and they do not desire their mate to have sex with others. It's usually a (selfish) agenda!
Falling "in love" and becoming "emotionally invested" in someone causes us not to want to share that individual with anyone. The very thought of someone you're madly "in love" with giving someone else "pleasure" is enough to drive a lot people crazy.
Being "in love", fear of losing them, and imagining how you'd feel if they were having sex with others is what causes people to (choose) to make promises of monogamy. If you're not "in love" it's a lot easier to be open to having someone you date seeing others.
Bottom line is whether one wants to be in a monogamous relationship or have the ability to have sex with whomever they want whenever they want the only solution is to be honest about it and seek out "like minded people".
Problems arise when you get with someone who does not want what you want but they pretend to be on the same page as you!.