That’s really weird, I thought your reason for wanting to room together could be private.

When I did the same thing (I’m female and my bf is male) they did ask me my reason for wanting gender inclusive housing I told them I was more comfortable rooming with someone I know that happened to be male, than I was rooming with a stranger. And this was true. But I honestly felt like I could have told them the reason was personal and they wouldn’t push. I never explicitly told anyone my bf and I were dating but nobody asked, not even the RA. I am LGBT but it didn’t sound like that was a requirement.

I would just apply outright with your gf as your desired roommate, can’t remember if you have to email or fill out a form but just go ahead and do it. Don’t pretend to be LGBT and maybe don’t mention you’re dating, just say it’s what you’re most comfortable with.