There was a movie I had seen a long while back, about 17 years ago, so I remember very little of it, but I will list what I do remember.
Probably a fantasy movie….Seems like it was in a cave, or underground facility. The girl was leading a guy inside, she was wearing a black helmet and a black thong. They were sneaking in. At some point the guy gets captured, and then is supposed to have sex with someone that the queen picked, a pit of women, etc….but the female that snuck in with the man ends up tricking the queen, and she has sex with the man instead.
I believe all the guards were female as well.
Thats all I’ve got.