For some reason some people (def. 2) seem to think that heterosexuals are all homophobic or think other sexual preferences are 'wrong'. Really, most heterosexual people don't have a proplem with homosexuality at all.
Heterosexual is the most common sexual orientation in the world, not because everyone is secretly gay and don't want to come out with it, but because people are born that way. However quite a lot of the new generation are gay or bisexual so this could change soon.
So please don't think that heterosexual people are all completely anit-gay, only straight because it's their religeon, secretly homosexual, or anything like that. Not all heterosexuals make it their life's work to abuse homosexuals. We've usually got better stuff to do.
Only tiny minorities are exclusivly heterosexual or exlusively homosexual (somewhere between 2 to 5% each); most are somewhere in between those two extremes.
Slang terms for heterosexuials include straight.
What causes heterosexuality? People always ask what causes pan-, bi-, a-, and homosexuality, but hardly question heterosexuality.
This is obviously the most common sexual orientation in the world, due to biology. (You can only get offspring if a male and female have sex) and probably due to religious and social factors (it's a crime in some places to not be heterosexual, and many religions condemn homosexuality/bisexuality)
However, just because it's the most common, and "socially/biologically/religiously" corrct, doesn't necessarily mean homosexuality and bisexuality are wrong or "weird".
Everyone should have the choice and right to be what they want to be, including their sexual choice. It's in no one's place to judge or condemn people because of their sexuality. Just like it's wrong to judge people based on his/her race, sex or socio-economic class.
So I am half heterosexual? lol.