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.