Since my post got deleted, I can't remember who was complaining about the game crashing and getting a fatal error. I managed to get a fatal error by doing this stuff in this order:
1. Spawn in Aoi
2. Maya go Nude
3. Tell Aoi to follow me
4. Possess Aoi
5. Aoi go Nude
6. Possess Maya
7. Move the camera slightly observing Maya
8. Fatal Error
I think the order to follow gets confused with the possession and results in a null reference error for whom Aoi is supposed to follow, which causes the crash.
Have you tried it again to see if you get another error, otherwise it might just be a random bug or caused by something else.
-Edit. I just tried it myself, didn't get a fatal error.
-2nd Edit. Just flying around and finding caves etc, messing around with the quick slot inventory (tried to drag spear to it but couldn't), a little later I realize my bow is gone, I then put my spear in the weapons slots, few moment later and that is also gone. Anyone else had missing weapons?
-3rd Edit. I restarted and tried to recreate the bug, but it didn't happen this time.
Got a fatal error when I stopped intercourse a few minutes later. First fatal error I've had so far.