You think the conclusion someone has come to from their own "lived-in" experience is "disgusting?" Those are strong words...
If they "chose" their sexuality, then I question their ability to have a sexuality at all. That just screams "sociopath"...
Sociopaths often don't have a preference for either, thus making a "choice" much easier. Choosing to be gay in such situations may be beneficial for whatever purposes they're working towards.
And I don't sympathize with sociopaths.
So again... yeah, it is disgusting. If a "gay" guy says he "chose" it, cut that guy out of your life. He's probably trying to take advantage of you or manipulate you somehow... as sociopaths are wont to do.
Give him a break on this -- there are no allegations of illicit or abusive sexuality. If he is outed he is outed as much for hypocrisy as for homosexuality, and he is no more hypocritical than the antisemite with a Jewish grandmother. Even if one is anti-gay but homosexual one has shown a huge gap between beliefs and actions. The beliefs are unsupportable but the actions are supportable. I have no problem voting for an out-and-out homosexual or for a rumored homosexual who does not bash gays rhetorically.
Voters will get to decide whether they want a hypocrite representing them in Congress. I'd find it just as difficult to vote for someone who campaigns on "family values" yet appears on the regular customer list of a whore. In the Prohibition era I would have found it possible to support a politician who stood on either side of the issue of alcohol -- but I would have found it impossible to vote for a "Dry" exposed as a regular heavy drinker.
It is hard to respect humanity or needful institutions if one hates oneself.