(Snort.)
Assuming the survey results are i the general realm of accuracy, what I think you're seeing here is not the Creeping Spread of Teh Gayz, or Evil Recruitment by Sodomites, or Proof Positive that Homosexuality is a Choice. In a society (especially among younger cohorts) where same-sex attraction isn't subject to major legal and social punishment, people are able to answer more honestly (to others and themselves) these kinds of questions.
Call it the "Free Market of Orientation," if you like. You're free to seek the product — or products — you like with consenting adults.
So, yes, you're going to see an uptick in people who identify as something other than purely straight. You'll probably see an uptick in people who actually pursue relationships on that basis, too. That's not a matter of licentiousness or the collapse of morality as much as freedom, and a recognition that sexuality is a lot more complex of a subject than our political process has painted it to be.
YouGov | A third of young Americans say they aren’t 100% heterosexual
When A or B were the only options, it’s not surprising that those were the voices made. As we have lived with the sliding scale of homosexual to heterosexual, it’s not surprising that more folks are comfortable in other places along the scale.
I hope that marriage equality might also start a discussion about monogamy in the same way. I see that ‘they’ see monogamy as the default choice, but not everyone feels that way. Some want multiple partners, some want a singly partner, but hook ups on the side, some folks create relationships of more than two people. And some folks don’t want to pair up at all.
I hope we can soon begin to see folks who don’t marry (or marry later and are single into their 40s and up) as full member of the community, not just people who screw up the seating chart at dinner.