I have 0 idea of how to deal with it nor have i confronted him about it yet

what happened was it was around 11 -12 at night and i got up to use the restroom my sons room is right next to the bathroom so when i was walking past his room i hear some clapping i thought nothing of it and i went on to use the restroom when i was done i walk out and i hear what i guess you can call a moan so i decided to look in his room and see i went in quietly cause it was late i peek in and look and i see him on his b*** up in the air using one of my toys (this toy is a 12 inch double ended toy) and he is just sitting there doing you know what i was in shock and quitely rushed back in my room in shock

now i don’t know what to do