So you're thinking about going French in your relationship – and we're not just talking French kissing. If a menage a tois seems appealing, then you may want to read up on the dos and don'ts of having a threesome.  First of all, choose your cast of characters carefully. A threesome tends to originate when an already romantically involved couple gets the idea to bring another person into the bedroom with them. If that's the case, then there's the risk of hurt feelings and post-tryst awkwardness. It's a good idea to talk out what each of you wants to get out of a threesome before it even happens. Establish the acts that you would and would not be comfortable with, and that includes anything you or your partner might do with the third party. Consider whether boundaries need to be set – e.g., whether you or your partner are OK with oral sex but not actual sex with the third person, etc.
It may sound less sexy to go into the experience with a plan, but when you do, you get everything you want out of the experience – and nothing you don't. What are your reasons for wanting a threesome? Doing it to please your partner or save your relationship isn't the best idea. Is it a means to spice up your existing relationship or someone's cheating fantasy? People sometimes treat threesomes as an excuse to have sex with someone else – be sure that's not the case going into it. The third person should be an acquaintance, not a super-close friend of either partner. Choosing a partner's BFF – particularly if it's the other partner's suggestion – could imply that you've had fantasies about the person and may put a strain on the friendship. It may create tension afterward if someone gets attached to a person who you see frequently outside the bedroom. So remember, three isn't always the magic number.