Jealousy in relationships can be a double-edged sword. For one, it conveys that you genuinely care enough about your partner to get bothered at seeing him, say, get friendly with the blonde bombshell who works at the local convenience store. On the other hand, jealousy can signal deep-seated insecurities and communicate that you're afraid your partner may bail on you for someone prettier, smarter, or more successful, for example. I think it's normal to become a little uneasy when we think about or see our partners talking to someone they might otherwise be interested in if they were single. But if we can put our full trust in that person, there should be nothing to worry about. Let's not be naive, folks: We're all human, and naturally we're going to find certain people of the opposite sex -- other than our partners -- attractive. But just because your boyfriend or husband might find her attractive and seems to enjoy conversing with her doesn't mean the...