Hi there :-)
Well, my boyfriend really wants to have a FMF. We've had several MFM's, so this seems like the next logical step. But I feel a little bad, because when it came to the MFM's, everyone was excited and so into it. My SO said he loved seeing me with another man, and he was a little bi-curious himself. So it was a great experience for everybody.
When it comes to a FMF however...I just can't seem to drum up any kind of excitement. My boyfriend wants to see me and another girl mess around, but that has about as much appeal to me as washing dishes. I tried to explain this to him, that I'm not bi and have not the slightest desire to be intimate with a woman. I tried, for my boyfriend's sake, to have a girl/girl fantasy, but there is just zero appeal.
Another thing is that, while so many on here talk about the thrill of seeing their partner with another person, the idea of that just...does nothing for me. I'd like him to have the experience of being with another woman because I know he'd love it, but the idea doesn't really send me into orbit. I'd be willing to just sit in a chair or something and watch him and another girl for his sake, but he wants me to be part of the action as well, and the whole idea just seems...boring. Really boring. However, I do love watching him with another man, though. Which doesn't help him too much here.
So what should I do? I know that I got to have my cake and eat it too, and now it looks like I'm trying to stop him from having his fun. He wants to see me with another girl so badly, which I understand...but it is starting to piss me off that he won't let go of his wishful thinking and keeps on insisting that I am bi and just don't want to admit it

I wouldn't want to get into something with another girl and become totally bored and make the whole thing completely half-ass - not to mention how unfair it would be to the other woman, who'd be expecting a genuinely bi lady.
Is it possible that once I get into it, I might like? I can see where it would turn me on to see my boyfriend getting turned on, but isn't the point of a threesome that every participant is equally excited? I feel like I'm robbing him because I'm not into girls or into seeing him with girls. Is this my fault? I don't think it is, but I feel really guilty nonetheless. Any advice?