So during a bout of tagging I would tend to come across these sorts of images where hands would be drawn entering from off_frame:
Im sure hands would apply and it seems as if most of these are pov as well.
There were also images with girls having sex with a partially visible lower half
I was thinking of adding out_of_frame but that tag only has an odd 25 images or so / off_frame but that doesn't exist.
Updated by jxh2154