A lot of gay people will stay in the closet too.  A cousin of mine was married to a man, and then got divorced because she was interested in women.  My (female) best friend's wife dated guys in high school to appease her parents (who sent her off to conversion therapy at one point).  She didn't stop being a lesbian, she just dated guys because it was what was what her parents expected of her.  She never gained an attraction for men.  You wouldn't exactly call her straight when she dated guys, despite not being attracted to them.  


Some people are bisexual, and some people are confused about what they like.  Those feelings can often be further confused by social pressures.  I have a gay friend who most people would have assumed was straight.  He often spoke out against homosexuality too.  Then he came out as gay, much to the shock of everyone.  Much of his family disowned him afterwards.  Turned out a lot of his feelings were repressed until he reached his late twenties.  


Discovering your sexuality is part of getting older.  You might be attracted to one, or even both.  Some people aren't sure what they're attracted to.  This isn't unusual in the slightest.  


In the end though, I don't think it matters if it's a choice, biological, environmental or what.  What they do with other consenting adults is their own business.  Parties uninvolved have no right to say what they should and shouldn't be able to do.  


I've also known some trans-gender people.  One in particular it certainly wasn't a choice for her (and yes, I'll refer to her as a her, because that's what she would want.  I'm sure some people would disregard their wishes, but I'm not that callous).  She killed herself because her father would not accept her for who she was.  She hated herself for being who she was because her father made her hate herself for it.  Eventually she couldn't live with it.  She didn't make a conscious choice that she didn't feel like a boy.  She wished that it was, because then she could have just been the boy her father wanted her to be.  


People want to talk about right and wrong.  Treating people like human beings regardless of their orientation or their gender identity is what I would call right.  Denying them the right to go to the bathroom, or to get married to someone that is the same gender they are, that's what I would call wrong.  Plain and simple.   

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