Contrary to popular belief not every man wants a 3some. There are a few of us out there who just don’t get all excited about being with two women and perhaps your boyfriend is one of those.
Now I am not for “Talking Someone into a 3some” This is something that they either have a desire for or they don’t. It’s kind of like religion, you will never convert someone who doesn’t want to be converted, all you can do is get them to fool themselves and you until the situation finally explodes.
Now that’s not to say that if it’s something you have an interest in, that he shouldn’t at least give it some thought. Our partners should be willing to try accommodating us as we should try our best to accommodate our partners. So I would first off take Xero’s advice and look into swinging and threesomes and some of the rules and issues that can come along with such a lifestyle. Then if you still think this is something you want, discuss if with your boyfriend, see if you can’t at least get your feet wet by joining a swingers site and testing the waters just via email and get to know some of the people out there.
Many people tend to view swinging as the last ditch effort to fix a broken relationship and while this can be the case, it really isn’t what the lifestyle is about, so you may need to reassure your boyfriend that this in no way reflects on his ability as a lover (Remember men have pretty fragile ego’s when it comes to sex) and that this is something that you really would like to look into further.
You didn’t mention why you wanted to look into a threesome, was it for you to be with another woman, or to see him with another woman, or something else? I ask because you can have a successful relationship when only one of you is in the lifestyle especially if your interest is in other women. For some reason a woman having sex with another woman seems much less threatening than a woman having sex with another man. You just need to be open with him and yourself as to what you want, and what you hope to find by bringing others into your sex life.