If you’re thinking about having sex with a friend, be very careful, because it is not easy to preserve a friendship once you have sex. We think we can control our feelings, but it's not so simple.

  • If one of you becomes romantically attached as a result of the sex, the friendship will probably not survive.
  • If you've done it before, and you know you can keep your feelings in check, you might be successful, but what about your friend? Are you sure he or she is aware of his or her own feelings and motives?
  • Think about it in advance and talk about it a lot.
  • Are you going to keep dating others while you're doing this FWB thing?
  • What if one of you falls in love with someone else?
  • What if you just want out of the deal after a while?
  • What if only one of you falls in love, instead of remaining friends?

Keep talking throughout the FWB arrangement It sounds a lot more fun and easier than it really is.

The benefit is being able to have sex with someone you know, rather than a stranger. The disadvantages are: It could be the end of the friendship. One person (usually the woman) could fall in love, while the other (usually the man) doesn't want to pursue more of a relationship. It may keep you from finding a real relationship, because you're too comfortable to look.

For men, FWB is what they want -- sex without responsibility. They also tend to take it for granted, and still be attracted to other women.

Most males have fantasies about having all the women they want. Women, on the other hand, tend to become emotionally attached when they have sex. (Men actually do, too, but they don't want to know they are. That's why they often don't realize they feel something for someone until that person is gone.) Women's fantasies are about a monogamous relationship.

If you start to develop feelings, pay attention! Don't ignore it. Let your partner know, and watch the reaction. If you don't get a positive response, cut off the sex. That's the way to see if the other person is also emotionally attached or not. Don't languish in a friends-with-benefits relationship when you want more. If he suddenly meets someone else and marries her, you'll be devastated.

If you want to cut off the sex, you need to explain why you're doing it. “I'm developing deeper feelings for you, and since you don't seem to return them, I have to stop having sex with you. I'd like to still be friends.” Or, “I can't even be your friend for a while, because I'm grieving.”

Maintaining this type of relationship is not easy for anyone. It only seems easy at the beginning. My office is full of people who had their hearts broken this way. Older people tend to be a little wiser and more cautious about it than younger people, but all ages get hurt.

Don't just let things develop on their own. Definitely talk about it beforehand, or as soon as possible. You need to establish that the friendship is important to both of you, and you don't want to ruin it. You also need to talk about feelings, to open that subject for future discussion.

  • If you want to turn a friendship into a full-on relationship, and you’re serious about it, then you need to talk about that, too. Your friendship will be altered forever when you have sex for the first time. You have things to lose here, and things to gain.
  • Make some agreements, discuss the above questions, and keep talking about it.

Back to being friends
Friendships that go from friends to lovers back to friends can be very close, because you know each other so well. The first thing you need to do is talk about it. Make a deal that you won't do anything that would jeopardize your friendship, and stick to it. (That means, acting as a friend, and not acting jealous if he/she has a date.)

The more emotionally mature you are, the easier it is to re-establish the friendship. Openness increases intimacy. So friends who can talk about everything feel closer than friends who can't.

However, friendships have more limits on sharing than lover relationships do. If you’ve found someone new, you have to consider your sexual partner, too, who might not like his or her privacy invaded.

It is possible to re-develop a friendship after the romantic line has been crossed, but it's not always easy. If both of you are in agreement that you were better as friends, re-developing the friendship is easier than if one of you still wants the romance.

Surprisingly enough, many people do become friends again after they've divorced or split up. Here are some guidelines for doing that successfully.

So, your ex has been hanging around, helping you out with things around the house, eating dinner with you and the kids, or just calling you up to talk about good times in the past. Old, friendly feelings seem to be coming back. Can you really revert to being friends? Here’s how to see if you and your ex can make it work.

  • Go very slowly. It takes time to get re-organized as friends. Talk about your friendship and tell the truth. If it’s going to work, it goes better if you go more slowly, and you’ll have a chance to build a better foundation than before.
  • Treat it like a new friendship. Start from the beginning, and do it differently—you have to figure out the difference between being lovers and being friends.
  • Be conscious about being friends—talk about what you miss about your friendship—if you cannot talk honestly about what changed and what to do differently, you won’t succeed.
  • Make sure your friend wants the friendship as much as you do. If there are unresolved old feelings, you need to talk about them.
  • If you run into difficulty, seek therapy to repair the friendship and resolve the lover relationship.
Author's Bio: 

Tina B. Tessina, Ph.D., "Dr. Romance," is a licensed psychotherapist in private practice in Long Beach, Calif. since 1978 and author of 13 books in 17 languages,  including The Unofficial Guide to Dating Again and Lovestyles: How to Celebrate Your Differences. She publishes the Happiness Tips from Tina email newsletter, and the Dr. Romance Blog. She has written for and been interviewed in many national publications, and she has appeared on Oprah, Larry King Live and many other TV and radio shows.