I secretly film every girl I sleep with
Why would film the girls you sleep with?
I've got a lot of fangirls, so I have plenty reasons to do so.
Filming someone without their knowledge is a major breach of trust and illegal in most circumstances. Having "a lot of fangirls" is not a defense. Why not request their permission?
They don't mind! It's a great way to remember them!
You don't know if they mind because they don't even know you are recording them. You need to stop doing this because it's wrong and you could get into a ton of trouble.