I’m having issues with the little girl I baby sit !

(this May be the wrong group)

This may be a bit long but here it goes.....

I have a 5 year old son and we have been living in a new town for 1 year so we don’t know any other kids for him to play with.

I started baby sitting a 5 year old little girl and a 2 year old little boy . So the 2 year old is such a good sweet little boy . But the little girl knows a lot about sex that she shouldn’t ! She is 5 !!! A few days ago she told my son to lick her middle spot and my son came running to tell me . Then she says my son is being nasty by running his 2 toy cars together . Like what ? How’s he being nasty . Then she says her little brother is making nasty noises ( he’s 2 ) and I said like what ? And she does THIS FAKE MOAN TO ME !! y’all my heart sunk . She does have 3 older brothers but the oldest one is only 12 ! . If her other brothers knows so much then how do there parents allow him them watch that ??? So I talked to her parents and all they say is “I don’t know where she’s getting that from she doesn’t do that at home , maybe it’s her brothers“. well yeah she’s not going to go tell her parents what she knows . Everyday its something new and the parents aren’t doing anything . I don’t want MY SON to learn about this yet . Ive tried talking to her about how did she learn about this and all she says is idk how I leaned it . Her dad works night shift and her mom works day shift . I don’t think things are happening at home but I don’t know what’s going on 😫 I’d like to continue baby sitting them because I’m able to have my own spending money and not touch the bill money my husband makes . But no longer know what to do . I explain that that’s not allowed at my home to her . Idk how to talk to her with her being so little ! This disgusts me but I know she’s just a child .