Yes, mrfisher,
My former mentor and researcher Paul Okami, was the principal investigator of an 18 year longitudinal UCLA study on parental co-sleeping and witnessing "primal scenes," i.e. parents having sex in front of children.
I've attached the abstract from The Archives of Sexual Behavior, probably the most respected sexual science journal next to Journal of Sex Research.
For those who are interested, there is a link to purchasing the entire article - it can even be done online.
As to experience with clients - I may have had one or two during my intern years, but if I recall correctly, these women were so massively abused, that witnessing primal scenes was the least of their worries. One girl had grown up in some sort of cult and she had such chronic PTSD, that she was most likely damaged permanently. Another had a mother who was a drug-addicted prostitute and had lived with her on skid row. Hardly a kid who just stumbles upon his/her parents gettin' it on like a good married couple. But....
I personally have witnessed my parents having sex - twice! Needless to say, they were both very accidental. The first time I must have been 8 or 9, and I didn't really think they were having sex, because mommy had a robe on and Daddy was lying on top of her on the sofa [just shows how innocent children are, LOL.] But she was making noises like Daddy was hurting her, and that's precisely what I thought! So I leapt out of bed with big eyes, only to get my Dad all perturbed, stop the action, and quietly lead me to bed, while explaining that Mommy was alright and there was nothing to worry about.
The next time, I was about 14 and I caught them by simply walking into their bedroom to look for something. At that point, I was a very defiant teen, and so instead I made relentless fun of them, calling my mother an old bag who looked stoopid, and my dad an idiot...or something to that effect.
And as you can see, I must be very damaged, because not only am I a marriage and family therapist who specializes in human sexuality - I also give free advice on this very board!
Now as to my professional judgment on this one: I would never advise my clients to have sexual relations on purpose in front of their nine-year-old daughter. It's one thing to practice parental co-sleeping with infants or toddlers and have some nookie in the hopes and beliefs that the little one is asleep. But one has to examine what values this sets for the daughter who is not only walking and talking, but also thinking and analyzing at age nine.
I don't think witnessing the act itself will create "severe psychological problems." Her problems will come when she attempts to integrate her value system with others. Of course, if she decides to join a hippie commune in Santa Rosa and live on ganja and wine, that's another story altogether.
There are all sorts of customs and cultures in this world. We have cultures where mothers fellate sons at a certain age, purely for ritual purposes. We have ritual circumcision [oy vey, even a bris in Crown Heigths would qualify] in people's living rooms, we've got scarrification, we've got very public sex acts among tribes..all in the name of some ritualistic beliefs.
How you practice sex is very much part of your culture and your values. Most parents who live in our Western society would have very little intellectual or emotional justification for having intercourse in front of their pre-teen or "tweener" daughter. In fact, in our culture, it seems agreed upon that while females mature early physically, they mature much slower mentally, and the trend seems to be to hold children back from TMI.
Whenever you do something with, for, in front of, or to children, you have to ask yourself: HOW WILL THIS BENEFIT THE CHILD? If you can provide a sound rationale for why it's beneficial for a child to watch parents have sex, not by accident, but by purpose, then by all means, let us hear it and let us all take these valid points into consideration prior to making judgments. But I would venture to say that there's a lot more "unconventional behavior" going on in that family, aside from exposing the child repeatedly to "primal scenes."
Child abuse it ain't, but....how will it improve the life of the kid?
the Love Goddess