I have, but there's a reason. It was when I was doing theater stuff during the summer in high school, and we were using the different restrooms for storing paint and stuff (don't ask, it's a long story), so I ended up going into a ladies room at one point, but it wasn't being used or anything.
At least I think that's what happened, it might have been the other way around where we used the guys room and there were girls in there. I don't really remember, now that I think about it. Oh well!
I really appreciate the Kotaku article about being gay in games, etc. But, you know, of course I did. It's nice to have games where you can do things like that. Though, I don't really think the options for that in ME3 were great (who wants to date Kaiden?), but that's just me.