Sexual desire seems to be a curse for men

[Belacqua]

I view it a bit like a game, some people are on tutorial mode and some people are playing Doom, on the highest difficulty with no cheats only using the knuckleduster.

Its a dog eat dog World and after all the workplace cheating I've seen going on with my own eyes I've become skeptical of the value in official relationships and marriage.

I currently have children with a woman I like and I don't cheat or pursue other women.
When I watch social media I see videos on how men should act, dress, live, down to the right amount of eye contact to give women. It makes me glad I'm not involved in all that anymore.

I'm not innocent though, I've only calmed down after spending over a decade pursuing anything that moved on any kind of social website or app I could find.

If you read about the upper classes in different societies, sexual monogamy was not always required. Usually for men, and often for women, there were unwritten customs about how you could have an active sex life outside of marriage. 

Generally the idea was that marriage was an arrangement for the good of the family line and for society -- not the individual. Once the couple had done its duty and produced an heir and a spare, different sexual rules came into play. So for example in upper-class Vienna until the War, both men and women frequently took lovers. The rules were that the lovers had to be from your same social class -- no open fooling around with the gardener. And the side relationships were expected to be somewhat devoted; too much switching around would make you seem unserious. 

In Italy it was normal for a married woman to form a semi-permanent relationship with a paramour. He acted as her social support and guide as well as lover, and as long as it followed the unwritten rules it was accepted in society. Husbands wouldn't complain because they were likely acting as paramour for some other lady. Again, the paramour had to be of the same social level, or occasionally a younger man who seemed to have a promising career. For example, if the lady's husband was a general in the army, the lady might select one of her husband's lieutenants or adjutants. Not a common soldier, though. This was accepted and the only trouble-makers were people like Byron or Casanova who tried to be the third unofficial lover, offering sex but no social standing. 

Japan had similar arrangements. Often of course the men were freer than the women, since making sure that the children were legitimate was important for inheritance reasons. But unofficial half-siblings were not unheard of. 

It would be interesting to hear about how the lower classes handled these things, but they tended not to record their lives in writing as much. 

Anyway, it appears you're right that lifelong monogamy is a difficult thing to demand, and different societies have found ways to accommodate this.