Sex is great - most of the time. It's a good way to foster intimacy with a partner, release pent-up frustration, and of course, make babies if procreation is the goal. But there are times when sex isn't a great idea and can end badly. Here are a few of the times when getting busy can go bad. First, when sex poses a physical threat - as in, it's not consensual - then it's obviously a bad idea. Sex via coercion or out of obligation isn't a good experience and can chip away at self-esteem. Don't have sex just to satisfy a partner, particularly if you believe it's the only way to keep him or her with you. It's hard to say no when you are really into your partner, but giving it up so he or she will be into you never works. While condoms protect against a lot of problems, heartbreak isn't one of them.