Men are more sexual than women. The majority of adult men think about sex at least once a day. Only about one-quarter of women say they think about it that frequently. As men and women age, each fantasizes less, but men still fantasize about twice as often. Men want sex more often than women at the start of a relationship, in the middle of it and after many years of it, while (most) women seem to fade away.
The reason men seem obsessed with sex is that they experience it differently from women.
For women, it is more about the anticipation and how you get there. It is the longing that is the fuel for desire. Women’s desire is more layered on emotion. They will often be "in love" before having sex.
Men don’t need to have nearly as much imagination. For men, sex is their way of propagating the species - it's a natural thing to want more than one sexual partner.
Monogamy is a man-made rule: look at the Bible - David, Solomon..many of the strong influential leaders had more than 1 wife, and many concubines. So why should we be worried about having more than 1 partner? I think not.
After all...variety is the spice of life!