My daughter went thru a time like this. I sat by her bed until she fell asleep. When she finally told me there was something under her bed (smile) we made up a spray bottle of scented water, each night we sprayed it under her bed to keep that little monster out of there. I swore solemnly that this type of monster hated this smell and would never ever get near it.
It worked.
Then if she woke up, she would try to come into our bed, we did the same thing already mentioned, put a pallet on the floor. She could choose her cozy (monster proof) bedroom, or sleep on our floor. (left unsaid was the fact that our room had no monster repellent <g>)
hmm Could he have heard you guys making love and assumed from noises that daddy was hurting you? He may also be trying to protect you. kids get funny ideas sometimes.