I suspect I’d be flattered with a touch of uneasiness. Subject to reevaluation on details of the fantasy–for instance, if the fantasy details were, say, dahmer-esque, I’d pretty much bury the needle on the uneasy side, and I wouldn’t feel flattered at all anymore.
As far as you know, I do. 
It would probably be hypocritical to say anything other than depending on who it was, my reaction would range between “well good for you” to “you want some help next time?”. I actually have been having this conversation with a couple of my friends over the last couple of days before I even noticed this thread. I have told a couple of people (who I wasn’t in a relationship with) that they have been the target of my masturbatory fantasies before, and the responses have ranged from “I want to put a shotgun down your pants and pull the trigger so you’ll never be able to do that again” to “aww, I’m flattered.”
Seriously though, what people do in their own homes with themselves, as long as it isn’t hurting anyone else, should be their own right. If someone…and I don’t know why they would WANT to…wanted to use me, I don’t feel I have the right to say that they can’t (not that it would even stop most people anyway), and if they actually had the guts to tell me, I would at least try to be polite about it. Now, if it were some stranger who came up to me on the street, that would be a different matter…
oh, and for the record, one of the dopers on this board HAS been the target of my fantasies a couple of times, but it would probably be highly inappropiate to say who (so everyone just assume it’s you).
Well, I think this is a much more complex question than it sounds. There are so many possible variations, as many other posters have pointed out. But, assuming it wasn’t said with the intention of shocking (yeah…good luck!) or hurting (wouldn’t do that, either) me, I’d be flattered (male or female) and, most likely, confused. I don’t understand why anyone wouldn’t be flattered, under those circumstances. Not only does this person find you sexy, but they also think you’re mature/evolved/sophisticated enough to handle the information. I can’t think of many nicer things to say about someone.
The confusion would arise in cases where there’s either been no previous contact or no indication of any interest by the other person. For a stranger to fantasize about me would be pretty odd. For a friend to do so would be less odd. At least (s)he would know something about my personality. 'Cuz, really…ain’t no one gonna fantasize about this body, any more.
It would make me feel a bit pleased, but a lot self-conscious. I guess I know I wouldn’t be in Real Life what I could be in anybody’s fantasy. So, yeah: pleased that I qualify for Fantasy in someone’s head, but waayy too intimidated to follow up on it.
FISH
um … lieu … I had this dream about you last nite …
A female friend of mine over several years (we had been flirting very lightly on occasion, but never anything in-your-face) once approached me in a similar manner.
This particular day we’d spent the afternoon together just hanging out. As it got time for us to part she sent me this radiant but slightly troubled smile, we’re both standing up about to head each to our own, and she pulls me close and hugs me goodbye a bit tighter than usual. I sense something is on her mind, but don’t want push her or to ruin the moment. She was in a very happy relationship with the love of her life, and although I always enjoyed being around her, I respected that and never expected more than the platonic friendship we’d shared for a long time already between her and me.
So I just squeeze her hand a little tighter and look at her. Whereupon she leans in and whispers please… please don’t get me wrong way, but I really need to bare my soul for you… she hesitates a moment as if searching for words. Of course, I reply. I have no clue yet what’s coming. So it hits me like a sledgehammer. Then, staring straight into my eyes, with a low whisper… would you call me on the phone one day and masturbate with me? Still holding my hand. My heart skips a beat before thumping like mad. Blood rushes to my head and time stops. What the heck is going on here?
Now this is a girl utterly out of my league for anything other than a platonic friendship. Best personality ever, openminded and honest, gorgeous looking, great sense of humour. Somewhere in my mind a siren starts chiming and a warning sign flashing that it’s a joke… get a grip man… she’s just messing with you for a laugh. I look at her again and see she’s biting her lip anxiously and her eyes are playful yet dead serious.
To make a long story short - she had been fantasizing about me for a long time while pleasing herself. She loves her man completely, but he’s okay with her having fun elsewhere as well as long as it’s all in the mind. Being that we’ve been hanging out together for close to three years she of course knows I’m single, and says if it wouldn’t hurt me in any way or mess me up emotionally - she would love to be with me. Like that.
I didn’t see her again for a coule of days, but when I eventually did - it wasn’t in person. Without going in further detail… over the next weeks and months she added several new dimensions to my definition of the word sex. We never made love in real life. She’s happily married to her man since then, I still see her, but we rarely talk sex openly. Our relationship is as good as it was before any of this happened, and we both know the added level is a fantasy and that’s how it’s going to stay. I’m not complaining. The night she opened up to me like that will always remain one of my most treasured memories.
Awesome sig, Fish!
Great story. Thanks for sharing it with us. And, welcome to the board. 
If a woman confessed that she had sexual fantasies about me, I would simply accept it as my rightful due. I have always just assumed that all women who know me, and many who just see me on the street, have sexual fantasies about me and think about me, not just when masturbating, but when having sex with their husbands, lovers and/or girlfriends.
I would, in short, be gracious. They can’t help fantasizing about me, why give them a hard time for doing so?
Being happily married, knowing it would never really happen, I’d probably treat it like a straight line and say something like,
“Oh, jeez… I hope you didn’t hurt yourself! Thank God it was a fantasy…most women have trouble accommodating my size and tantric skills.”