i am a divorced man of 7 yeras with 2 daughters aged 12 and 14. my ex remarried last year and both my daughters live with their mom in the week and with me at weekends. i confess to being very worried over my eldest daughters behaviour. i may be over reacting but my daughter has taken to wearing very revealing clothes, short skirts, tight fitting tops and im sure sometimes she's not even wearing a bra, as i couldn't help but notice the outline of her nipples more than once. more worrying is what my younger daughter tells me what went on with their step father. to be fair he seemed a descent guy, he loves himself as he works out a lot and at 27 a good few years younger than my ex. until a few months ago he treated both my girls equally but now the younger one is ignored and the older one can do no wrong in his eyes. my youngest arrived last saturday morning as usual but looking a bit upset, she then preceeded to tell me that on friday night when my ex works she walked into the day room to find the step dad lying on his back with her sister sitting across him. he was only wearing shorts and a vest and her sister a skirt which had ridden up showing her panties and a crop top and no bra again, he was bouncing her up and down using his body strength. after a couple of seconds they noticed my youngest standing their and quickly got up, she is old enough to know it didn't look right and asked whats going on? he explained it was part of his weight training lifting a weight using his back muscles. when they later went to their room she told her that her step dad must of been able to see her tits as her top was so short, and her panties but she just laughed. i just don't know what to do for the best, if i try to speak to my ex she will think i am trying to cause trouble in their new marriage, my youngest may even be lying as she does get jealous, but i don't think so as i have seen the clothes she now wears, or maybe it is all totally innocent. this is what i had tried to convince myself was true, unfortunately i now fear the worst, my eldest arrived early saturday afternoon, her step dad dropped her off, that evening she showered and the next day we all had a great family sunday together. i took the girls back as usual and returned home. i know this is probably wrong but i always do their laundry sunday nights and this time being so concerned for my daughter i went through her washing and found her two pairs of panties she had been wearing at the weekend. i couldn't help but inspect them closely and my worst nightmares were confirmed, one pair you wouldn't know had been worn and the other which must of been the ones she was wearing when she arrived were crusty and heavily stained, i quickly raised them to have a quick sniff and as any man knows that smell of sex was so strong the mix of cum and a girls wet pussy can't be mistaken. i know she hasn't got a boyfriend so i have to think the worse. at the very least i know i must confront my daughter, maybe with her mother present. if anyone can offer sensible advice it maybe very helpfull.