What's your thoughts on Jealousy in a relationship?

Some jealousy is natural unless you feel absolutely no attachment to the person at all. I don't go overboard with it (my husband is welcome to have female friends, watch porn, and check out other women)- as long as he doesn't act on his attractions. I'd be freaked out if someone didn't get at least a little jealous when there was a possible threat of their partner being more attracted to someone else.