What's your source for this?  Moreover, your telling me this doesn't alter the fact that the article doesn't address the question.   

 Guys are either gay or they're not, whereas girls are allowed to experiment.   

 Who made this rule, and to how much of the world does it apply?   

 After college, the peer approval of this behavior greatly diminishes while society's approval will only gradually diminish with time, wrinkles, and gray hair. Consequently, a lot of girls quit after college. And for them, it's just behavior. They were the lesbians until graduation. The term doesn't make too much sense because they were never really lesbians to begin with, but it exists nonetheless.