Thanks to NOPkins and the women who posted here with their thoughts.
Here are a few more thoughts.
I don't know that it's even possible to compare girls and boys in this manner. Because of society we are given different messages about sex from the beginning. Women aren't supposed to like it; men are supposed to be studs. (This from CAC4.) There is a double standard as we all know.
It's hard to imagine anything that a mother could say to her son that would be as threatening as this type of innapropriate comments said by a father to his daughter.
My mother was not a sexual being in my eyes. My father was. (And I don't mean I consciously saw them as sexual beings. This was all subliminal stuff.) I'm sure she was uncomfortable with her sexuality. My father was not. Any display of sexual behavior between my parents was initated by my father. I know I saw/heard my mother rebuff him for making what she saw as sexual advances (hugging her from behind when she was at the sink, for example). I think her behavior was not uncommon for a woman of her generation raised in a Puritanistic society.
Now, when my father starts making his innapropriate comments and teasing it is threatening to me. Hell, his sexuality was threatening to my mother! (Or at least I perceived it that way because of what I observed.) Several of the teasing incidents occurred because my mother betrayed confidences by relaying information about me to my father. Double betrayal.
I think the only way that a boy's sexual development could be negatively impacted by his mother would be if she acted in an overtly sexual way toward him. I remember Lil posting about the way her BF's mother treated him and the impact it has had on his sexuality. This is what I'm talking about -- a mother whose behavior toward the son overtly sexual--confusing, inappropriate, possibly even stimulating. The message we get (got) from our society is that mom is supposed to be June Cleaver or Carol Brady, not Pam Anderson. And I don't mean to impugn Pam Anderson. She may be very Carol Brady-like at home with her boys.