what should i do about this situation: I have a 21 month old daughter, my roommate has a 4 year old son. every single time he is in anyway alone with her for even a second he does something sexual to her, he has tried getting her to take off her pants, he talks to her about his and her privates when he is alone with her. he tries to kiss her, he does things to get her anywhere between his legs. i dont change her diaper in front of anyone yet he goes out of his way to come back in the room knowing she is getting a diaper change. he lies about his actions even when he is caught. he has even pushed her down on the ground just so he could try and lay above her. i have tried talking to his mom about it, she has mentioned he has acted this way before, but she consistantly blows me off. i try and keep him away from my daughter and she gets pissed off because he doesnt have full range of the house (my daughter and i sleep in the living room. i have talked with a woman who knows us both, she has 3 boys. she said he does the same thing with her boys, trying to see their parts and get them to play with themselves in front of him. what do i do, i plan on moving but how to i get help for this family how do i protect my child?
While children are sexually inquisitive and curious, it shouldn't be a full time quest. Without knowing his background and what he is modeling or has been exposed to, it is hard to say why his is this sexually driven at four years old.
Here is one site, among thousands, with some guidelines for normal sexual development behaviors at certain ages.
His mother needs to step up and take action to enforce guidelines about inappropriate touching for himself and others. It sounds like she may have some sexual issues of her own that she is not willing to face at the moment.
If you observe this behavior and she isn't there or is unwilling to take action, then you should be taking action to divert his attention and tell him NO and why!