You don't be a father by sleeping with the kid! Sure, if you are an acctual father, and the kid is >3 and he is afraid of the thunder of something, that is fine. But if you are not related at all, you shouldnt even be sleeping in the same room.
If that did happen and the kid did want MJ to sleep with him, MJ should have had some common sence and said "no i will sleep in another room"
And if the parents were bad, thats what DSS is for!