The gay twin grew up as a heterosexual, married, had children. Then decided at some point he was not happy and was gay, divorced, moved to San Jose with a homosexual other, and now lives a totally liberal lifestyle. Claims his being married has not hurt anyone, forgetting what he did to his wife and two little girls. He still sees them, they are of course expected to accept his new lifestyle. He feels he is a good father.
Your anecdote sums up the fact that some people think that a fulfilling sex life is actually a right. It is a mark of immaturity and irresponsibility IMO when people behave in the way you described. Throughout our lives, we are faced with temptations and choices. Many people (both homo and hetero) make the wrong decisions based on what "makes them happy". For instance, a man may leave his wife of many years and marry his cute secretary. He doesn't "need" to do this. But he yields to his baser instincts and does it anyway.
In college, I was a theater major and was around a lot of homosexuals. A more sex-obsessed bunch you will never see. Of course we heterosexual guys were trying to score with cute the cute girls as well. We had to jump through all the hoops most guys do - take them out, buy them presents, etc. The gays just seemed to meet and immediately decide to have sex. A young and inexperienced guy could get sexual experience really fast by joining the gay clique. I saw several young fellows get snapped up by the gays almost on arrival on campus. I only know of one of those young fellows that left the gay lifestyle. He ended up marrying one of the more attractive girls and having kids.
The explosion of acceptance of homosexuality grows to a great extent out of the idea that a person has the right to be sexually satisfied all the days of his/her life.
Actually, I think it grew out of the de facto "ad campaign" we've been subjected to for decades by the "arts crowd's" ugly sister (i.e. mainstream media).