not sure if im going to be much help but my friend has a daughter with ds & i remember what she was like going through school (she is now 27) anyway she went to a special school & used to come home with ripped undies & bras etc & it was from the boys at school - she thought it was funny even though it was explained that it wasn't but she then started to flirt with other guys - this happened from around 14 on - she was always talking about boyfriends (still does) but never had any - i think she got it from watching tv & saw others with boyfriends & kissing etc & would elaborate on that & act the way they did (like the kids on H&A) the school said it was part of her exploring her sexuality but it was something my friend didnt want her daughter to be doing & talking about at that age - she did calm down but half the time i could never tell if she telling the truth or making it up
hope it helps somewhat to know you arent alone!