Question about making a video
Just ask permission, and if you're not experienced, try a practice run. I would bet that some girls offering doubles would have a friend willing to do hand-held video work that would help with the quality of the end art. Albeit at a bit more cost. But it would probably make your date more relaxed as well. I did a bit of nude photography back in the early 80s. Just stills back then and most of them looked like shit. But after a while I got some good'ens. They are right, the girl (or man) must be comfortable and not too nervous or it will look like shit.