"....a beautiful, sexy, caring, smart women at home yet still find the need to pursue other women?"
Great question. I always wonder the same thing! There are several possible things:
1) Desire and human nature. We crave for things we do not have and for more when we have them. Greed in other words, for when you have something you often forget how much it's worth just 'cuz you have it at your disposal.
2) His significant other may be beautiful, smart, caring and all, but she could be lacking in how to convey her care. She may not know simple things of life. At first he doesn't mind but as time goes on he gets sick of it, as anyone else would if he or she doesn't have patience.
3) She is all of that, but they have conflicting views in ideology, so he seeks someone else to fulfill that aspect.
4) They may not have sexual connection. And they may have disagreement on when and how. LOL! Really though, a woman is beautiful, intelligent and caring but she's human. She too gets tired and has her weaknesses as well as strengths. She can't always please someone.