Muehlenberg likes to trot out his "ex-homosexual" myth, like it's a trump card.
His "reasoning" is that if some people used to be gay, but now have a straight relationship, it can only mean that homosexuality is a "choice" and therefore all gay people can change.
You'll notice at once he's very quiet about applying this "logic" the other way round. There are countless examples (I've known many myself) of people who have straight relationships and even marry opposite-sex partners, only to years later, often after a prolonged period of torture, come out as gay and find real contentment and happiness in gay relationships. I'd be willing to bet the traffic going from straight relationships to gay is substantially busier than that going the other way.
Yet nobody (or at any rate, nobody sane) would claim that "ex-heterosexuals" "give lie to the myth" that people are "born that way". Nobody sane would suggest that anybody could therefore choose to be straight, and that heterosexuality is a mere matter of choice.
Anybody sane would see it for what it is: unfortunate people being pressured to live a lie for fear of the consequences (upsetting their religious parents etc). Just as nobody who doesn't have an extremist religious agenda to push would be in the least surprised that gay people, facing rejection from religious friends and family, may attempt a straight relationship and claim they are "ex-gay". Their behaviour may have changed, but you'd have to believe in bullshit like miracles to think their orientation had changed. They're just gay men living a lie. Hopefully for their sake their partners have low sex drives, as intimacy will be rare and oft avoided.
So please, Muehlenberg, put away your "trump card" - it's impressing nobody, and you just continue to embarrass yourself as to how little you know about human sexuality. Some people really are just gay - and it's time you and your fellow religious bullies just got over it.