I think if we had a way of pliting the population into equal sides we would find the spliting of gay couples and heterosexual couples to be about the same.
There are some humans who mate easly for life and some humans who just cant seem to ever settle down with one partner I dont really think what sex you are attracted to holds and bearing on if your a commited person or not.
I for one am a person who finds it hard to commit to one single person.
Although I have been in a relationship for 5 years and not strayed I still have not commited myself to it as far as getting married goes.
And thats a personal problem of mine and mine alone I dont represent the larget magority of heterosexual couples out there.