I am thinking that some people CAN change their sexual orientation, but others cannot.
Some people, Gay, Bisexual, even Straight swear that thier sexual desires have changed over time, but hardly ever because of something they did.
I think the change happens on ITS own, in the rare moments when it DOES happen.
Example: My ex boyfreind used to like women more than men. When he was between ages 13-19, he wasn't turned on by men the way he was turned on my women.
Although he found men visually attractive, the thought of sex with other men didn't excite him in any way. When he was 21, he said he began to find men more and more attractive.
He doesn't know why, but he just did...suddenly, the thought of naked women didn't turn him on anymore. It's like he was bored of women or somthing. He wasn't able to explain this to me that well.
Not to get too personal, but for the sake of argument, he said during masturbation the thought of men gave him a quicker and more intense orgasm than the thought of women.
So at age 21, he began to have sexual experiences with men, and found he enjoyed that more than sexual experiences with women.
HE considers himself bisexual, because he still finds women sexually appealing, but for some reason, no where as appealing as men. HE said he would rather date men than women.
He doesn't know what caused this change in attraction. HE says it may have been boredom, but whatever the case, his attraction to women totally diminished, and his attaction to men grew out of no where.
He stated that if he had a choice, he would choose to be straight. It would be much easier to like women again, because he wouldn't have to deal with the stigma from his parents, freinds, church, etc. But since choice is not a luxury that most people have when it comes to sexual attraction, he can't make that happen.