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I have these dreams that my mother is trying to have sex with me. I want to leave, but I freeze in place and can't move. I feel sick when I think about it. I'm a bisexual woman in a healthy relationship with a man. I don't know if this has anything to do with it, but I also have another problem: I really want to have an orgasm with normal sex. I can come if my boyfriend goes down on me or rubs me off, but it usually takes a long time. He's wonderfully patient but I'm still frustrated with myself. I always feel like I'm almost there, but then we'll have been at it for so long (two hours or so) that I dry up and it starts to hurt and the feeling is gone. Is there something terribly wrong with me?
Bad Dream, Bad Sex
There's only one thing about you that really worries me, and it's that you would ever imagine in your wildest dreams (and your dreams, you must admit, are pretty wild) that the perfectly normal way in which your sex life is unsatisfactory could have anything to do with your mother. I don't think that the Oedipal (not the right word, but "Electral" doesn't quite work either) dreams have any connection to your bisexuality either. Whatever's going on with your feelings about your mother is way too fraught and Freudian for me to touch, but I'm willing to bet it has influenced neither your sexual preference nor your sexual performance.
As for coming during "normal" sex, well, you already are. Of course you'd like to reach orgasm during intercourse, but please understand that if you did so, you would be in the minority, hence no longer "normal" yourself. Relatively few women (the number is unknown but often reported at about 25 percent, which is probably too low, but it's all we've got) reach orgasm purely through vaginal intercourse with no additional clitoral stimulation. This may seem unfair, but Mother Nature, admirable as she is in many ways, has never been known to play nice.
The feeling of getting "almost there" during intercourse is, regrettably, extremely common. It is also good news — if you're almost getting there, there is at least somewhere for you to get to. My advice: quit the grim, goal-oriented grinding (two hours is really pushing it, guys), don't let yourself dry out (there are many fine wettening products out there), and when the good feeling begins to fade, do something else. And no matter what happens — pay attention, this is very important — do not think about your mother.
I was rereading your column "Sister Act" and had a question. When I was maybe eight or nine, I'd play daddy and my sister would play mom. I don't know where we got this idea, but sometimes I would get on top of her (clothed) and kinda grind away to orgasm. I think we both knew we weren't supposed to be doing it, and if my parents came in, we'd quickly separate. So, is this at all normal? Also, is it normal that later as an adult I still desire her (I'm bi)? I'd never act on it, but I feel awful just for thinking it.
Sister Act II
I wrote a column called "Sister Act"? I wonder what it said? Probably something about how even socially unacceptable fantasies are harmless and, like ghosts and other apparitions, unable to affect things in the real world unless somehow incarnated, so don't incarnate them. Something like that.
Playing house, including the weirdly gender-bound role-play and the not-so-innocent grinding, is indeed common and even normal. Most kids get up to this sort of mischief once or twice and nothing bad happens (of course there's always that one kid who likes it a little too much). Cousins and next-door neighbors are the classic partners in crime, but siblings will do in a pinch, and to call this "incest," let alone "abuse," seems an unnecessary pathologizing of pretty harmless childhood exploration. This is all assuming that it stops at some reasonable age — preferably before puberty. It's uncommon to even remember the game all that clearly, let alone long to go back and pick up where you left off.
In short, while there are many definitions of normal as applied to sex, none can fairly be said to include sex with your adult sister. There is nothing to be gained by feeling awful about it though. We're not responsible for what we want, only what we do. Don't do anything — that includes saying anything — and you really have nothing to feel guilty about. Weird, yes, but not guilty.
Andrea Nemerson has spent the last 14 years as a sex educator and an instructor of sex educators. And she just gave birth to twins, so she's one bad mother of a sex adviser. Visit www.altsexcolumn.com  to view her previous columns.