How I started crossdressing

For me it started one early spring afternoon home early home from school. It must have been 1974. I have been curious for awhile on my sisters friends coming home to us to prepare them self for Friday evening party, so it happen quite often that I got to see her girlfriends in lingerie, and particular one girl age of .. was always wearing a see through bra and matching panties. On top of that she had thin white pantyhose. I was surprised each time that she didn't hide it for me, maybe she saw how horny and hard I became. So that Friday afternoon home alone from school I was thinking about that my sisters friends will show up again, which made me a bit hard and horny, and made me thinking if my sister have anything that I can checkout.... I went to her room and checked out in her drawers and found a nice white see through bra ,(which I never have seen her wearing) a white short satin slip, her white thin pantyhose (which she wore on her confirmation) and a almost see through tight white top. I undressed naked and started to put her nice lingerie on which was so nice and it made me harder that I never been before and that I started to oozing out precum which made her pantyhose wet and even went through to the slip I was wearing. I was posing infront of the mirror and found my self looking feminine and sexy, and believe me i couldn't get harder. I lay down on her bed on my stomach and put her sating covered pillow under me and started at once rub against it, I felt how the thin nylon was rubbing my hard "clitty" and my sensitive head. It was sliding so nicely on the two layers of satin, I was in haven. This was way too nice and the whole situation made me so horny that I couldn't hold my orgasm back and I started to shoot out cum in the white sheer pantyhose I was wearing and though them so I stained her slip too, ooh it was pulsating and pumping out cum. When I came to my senses again I realized that one hour had past since I started to check out for my sisters lingerie. My mom will be home soon. Better to clean up and saw that the slip and pantyhose I was wearing was all wet from my cum and even a small spot on the satin covered pillow. I wiped off the pillow and turned it upside down and went in to the bathroom, undressed and started to wash up the soaked lingerie. I had to use my sisters hairdryer to quickly make them dry. With 2 minutes in spare all lingerie was back in my sisters drawers and dry. My clothing was back on and I sat down i our kitchen when my mother showed up. (puh). An other thing I notised then that my nipples was really sensitive in her white sheer bra and has been since then, and gives me a nice sexy feeling to caress my nipples through a sheer bra.