In a way, your friend’s statement is a tacit acknowledgment of what sexuality experts have been telling us for years. Far more human beings are bisexual (sexually attracted to more than one gender) than we are culturalized to believe, maybe most human beings.
The end game of LGBTQ acceptance (which I doubt anyone today will live to see) is a world in which the gender of one’s sexual or romantic partners is unremarkable and irrelevant. (Not incredible. Past cultures in various parts of the world have approached that paradigm.)
In other words, we’re working for a world in which most people being “a little bit gay” is ordinary and accepted.
Of course as you point out so well, that sort of phrasing is problematic today. But let’s have faith it won’t always be problematic.