Yes, Exactly 2/1000 of a second after the concept was brought to my attention! (Classmates at school were discussing the topic.)
You actually just made my point for me. You had an immediate reaction, that wasn't a choice.
In order for it to have been a choice you made, it would have taken time for you to arrive at a decision.
You didn't need time because you already knew that you could not be attracted to the same sex.
There's a second part to the debunking of the "homosexuality is a choice" myth.
If homosexuality is a choice, then it is a choice that you can make or unmake at any time during your lifetime. So then, you could actually make the choice to be a homosexual right now.
Try it...try deciding that you are now attracted to someone with similar rather than dissimilar gear from yours.
So! You considered it, huh?
Not that there's anything wrong with that.