Honestly, middle school was when I was aware that girls play mind games with boys' hearts for their amusement.
If men are easily satisfied with a loyal, modestly attractive girl, what are women easily satisfied with? I will tell you what. Women are satisfied by MORE and if they see an opportunity to get MORE they will take it, damned the consequences.
Women are excellent liars, because you want to trust them. They know this and abuse it. They take all the fundamental building blocks of a caring relationship between two humans in the world and use it as their step ladder.
The worst part is that they mock men who don't trust them, calling them crazy, weak, bitter, jaded, etc. because they just can't resist getting their jollies at the expense of men.
They love cheating because they can enjoy breaking the heart of one and seeing him in emotional torment while experience the "new car" feeling of another guy.