That is fucking hot! Sick. But hot.
I was deflowered in a near similar situation except I was in my earlier teens and I was in my sister's schoolgirl clothes. I was a cutie, slim, effeminately smooth with a firmly tight virgin boypussy and hair on the questionably long side.
I was secretly jelous of all the attention my sister got from the boy'and men in her schoolgirl pleated skirt and lace bottom panties. I got so excited the first time I slipped into a pair of her lace bottoms. I have a friend that's the same way and we'd both dress up together.
By the time we were in eighth grade we were in eighth grade we were making out with older boys who didn't know we were boy's. That all started with us to the delight of both of our moms dressing us up in our sister's stuff for holloween. We ended up with a handful of thirteen to fifteen year old boys trick or treating with us. I had boy's hands all over my lace covered butt the whole time and graduated to my rosey cheeked pouty lip's giving in to an aggressive fifteen year olds penis. They didn't find out we were boys but they were pretty satisfied regardless.
It was my neighbor who saw my cute little panty wrapped bottom climbing in and out of my bedroom window dressed up to meet with boys in the park. He was the one who pumped my fresh little panty wrapped ass full of mancum. It took him a while to get it in too!