As you can read here, men in long term relationships have lower testosterone, these effects have been replicated in a few studies as well. So basically, women are enforcing a situation where they want men to be with 1 woman (themselves).

In an effort to put this as simply as possible, women are demanding commitment from men which makes them lose testosterone which then has the effect of men losing attractiveness to those same women.

Men need to protect themselves from this stuff, since we have all of the information today. As a man you can:

  • Never get married
  • Get your testosterone checked (especially after 40)
  • Making sure you're eating clean and healthy
  • Don't become complacent

Edit: Testosterone's effect on attraction since I figured this was common sense but people still being ignant