I was talking to a woman in her twenties who really enjoys giving her boyfriends anal sex.
She said, "I was first introduced to sex toys when I experimented with having a lesbian relationship in high school." Apparently, she begged off beaver, but kept the toys for working the boys.
"I don't fuck all of my boyfriends up the ass. But, I've really never had a problem getting guys to let me do it (to them). The first time, I usually let them pick out which toy I am going to use. I find this helps them and, depending on which toy they select, I can tell how much they are really into it."
Interestingly, she didn't describe her boyfriends as bisexual or effeminate.
Women, by their nature, are used to penetration as part of sex. Though, you might be shocked to know some radial feminist consider any form of penetration to be rape. Fortunately, most women disagree and we all are conceived and most of us born. (In the U.S., there are about 700,000 to 1,000,000 abortions per year.)
However, due to social and physical differences, men aren't typically open to being penetrated of course. For some men, it can be a life changing experience in regards to how they view women, their sexual orientation, or how they see themselves in sex roles. For example, many men will only "serve" dominate women after such an encounter and a few I've heard of aren't capable of achieving further erections leaving them open to being cuckolded.
Interestingly, she hadn't considered any of these outcomes.
I suspect she's had at least ten lovers who's lives she's changed for ever.
Anyway, there are a number of websites and at least one good book on bending over your boyfriend to search out if you are interested.