My fiancee has asked me if I would have a 3 some with him and someone else. (he did not name anyone specifically) I've thought about it before but I'm afraid it'll do damage instead of good to our relationship. Has anyone ever done this? With your boyfriend or fiancee or even husband? What did it do to your relationship? Did you have rules about if it was a girl and whether she could do anything to him or not? Or a guy and whether he could do anything to you or not?