STUPID HUMAN TRICKS

I'm sorry, I'm trying to understand this. Why would Jude Law be dumb enough to cheat on his wife Sienna Miller---With the babysitter (or Nanny) to his children from a previous marriage. Was Jude Law aware that he was either married to or engaged to one of the hottest women on the planet? Was Jude Law born stupid. I'm sorry, there are some things I don't understand. People are getting divorced much too easily and for such dumb reasons. People are looking for an excuse to escape marriages either by cheating or using physical abuse much too easily. People are being flighty rather than setting down with one romance partner much too easily. That's a shame because there more to romance than recreation and baby making functions.