First I’m not sure this is actually true. One might thinks it true based on certain gender ideas or anecdotal stories. Sexual behavior surveys indicate that about twice as many women have had same-sex experiences compared to men. I would guess that women are more open to same-sex sexuality because they are less likely to find it threatening to their self-image.

As for myself, I’ve had threesomes with both two guys and two women, as well as group sex with multiple men and women. Overall, I’d say that with more women than men the sex is “sweeter” and more mutual, where as with more men that women the sex is more “hardcore” and dominating.

(http://www.autoadmit.com/thread.php?thread_id=4084779&forum_id=2#36869088)