Right this happened a few years ago now when I was 13. Now being the only male child I had my own room, my twin sisters (14 at the time) shared a room and my little sister (10 at the time) also had her own room. We used to play fight like children do, and especially worse when our parents were out. Well this one time when our parents were out we started to play fight. For "fair" teams I was on my own (as usual)and my sisters were grouped together. So as we fought they managed to over power me and pinned me, the twins on a leg each and my little sister on my hands. One of the twins thought it would be funny to teach my little sis about the male anatomy, so they undressed me exposing my manhood. She thought it was hilarious and started to flick it, they pulled and twisted it until I had an erection. Again she found this hilarious. One of the twins ran up and raided my little sisters wardrobe. Got her school skirt, barbie panties and bra, ankle socks and little t - shirt and dressed me in it. Embarrassing or what and they told all their mates that a 13 year old lad was beaten, striped and costumed by 3 girls, one 3 years younger.