Yes.  I was at a friend's house.  He had a sister who was taking dance classes.  I don't remember who suggested it, but we put on her dance costumes -- mine was a ballerina with (at the time) at huge tutu.  I loved it.  We danced and pranced for quite a while, then his mom walked in.  She was really mad and we froze while she yelled at us.  She then paraded us downstairs to show his sisters who laughed and laughed.  I burned with embarrassment, mixed with great
excitement.  They moved a year later -- we never really played again after that.

That set off a youth in which on frequent occasions I dressed in neighbor's clothes.  Usually in summer when I had to mow lawns and feed pets of vacationing neighbors.  I thought it was great!  There're more stories there, perhaps another forum question could start it off.
 

I was "caught in the act" at least twice, while wearing my mother's clothes. It was very embarrassing and upsetting, of course, and I promised both times that I would never do it again. I tried to be careful whenever I wore her clothes, but there were two times when one of my parents came home unexpectedly. The first time, in June 1961, I had made the mistake of answering the phone and was talking to a cousin when my mother suddenly came home. She was obviously shocked, said nothing, and left immediately. A little while later she called me and said we would have to talk about this. Naturally, there was a confrontation with my father that night. They said I needed "help." I was very upset and tearfully promised never to do it again. I kept my promise for at least a year.

There were a few times when they suspected I had resumed cross-dressing, but it was several years before my father came home unexpectedly one evening and found me wearing a dress, petticoats, bra, girdle, stockings, and scarf. My mother had bought a two-layer, triple-tiered nylon chiffon petticoat about 1962 and I sometimes wore it. That was the only petticoat she ever had. It really made the dresses look full and fluffy. I enjoyed the way it felt, too. Anyway, I again promised never to do it again. After that, I did "slip" a few times. Then, about 1967, I completely stopped wearing my mother's clothes and never did it again. Later, in the fall of 1979, I bought my own female clothing and, within a few months, went public for the first time.

I was never forced to cross-dress. Once, however, I was asked if I would dress as a girl for a Cub Scout program. I refused. I hadn't started cross-dressing yet and I couldn't bear the thought of anyone laughing at me, as usually happened when a boy or man dressed as a female. After all, I was used to watching Milton Berle and other comedians in drag and they clearly did it for laughs. I was simply too sensitive to dress-up and have people laugh at me, perhaps because I had suffered enough teasing as a child because I was always tall for my age.

Much later, I would have people tell me how much they liked the way I dressed. Many people were fascinated with the many petticoats I wore. Generally, I found very few cross-dressers here would wear 1950's styles. There was one female impersonator, however, who did sometimes wear very full skirts with petticoats. Most cross-dressers I've met tend to dress as modern women.
 

Yes I was caught trying on a dress when I was almost six. It was real late at night when at night when I thought everyone was asleep. The woman I was boarding with scolded me and told me little girls don't wear dresses to bed. She then dressed me in a nightie while telling me this is what I should wear. I was then sent back to my bedroom where the other boy boarders slept. She woke them and introduced me as the new boarder and after much laughter, I was made to sleep in the gown.

The next morning, after eating breakfast while still in the gown, I was sent back to my room while the others went out to play. After a short wait, she entered with her arms full of her daughter's prettiest clothing. After much screaming and kicking, I was dressed completely as a little girl. The only thing of mine was my shoes. I can still remember the dress as if it was yesterday. I was then forced out the back door into the yard with the other children including her daughter.

It was not wonderful at the time and I withstood much humiliation and shame as the oldest boys kept lifting my skirts and laughing while telling the others to look at my panties. I was helpless as I could only cry. I remained in the clothes for the whole day including that afternoon when I was allowed to remain inside. I spent it playing with the daughter in her room. That's when I started liking the feeling of being a little girl. It was a soft pretty world that allowed me the freedom to be sensitive and gentle.

As for the long term effects, it's been fifty years since that happened and I'm still dressing up in the same style little girls dresses (custom made). Was the humiliating events responsible? I think so, since every time I dress up, I am not playing at being a little girl but at being again the little boy being put to shame and made fun of. Humiliation seems to be my driving force though there is a real calming effect too. I just plain like feeling soft, sweet and pretty even if it is just play acting. I only wish I could dress up all the time and enjoy the swirling skirts, petticoats, ribbons, etc. continuously. I love being a sissy boy.