I am a middle-aged male bank executive, 'normal' in every way, except that I like to wear women's crotchless pantyhose. I began this habit with a former girlfriend, when I borrowed a pair of hers, and now I wear a pair every day under my business suit. I wear no other underclothing.
Often, a female client will visit me at my desk, which is large and behind which I remain secreted. If the conversation is proceeding well, I will reach down behind my desk, unzip my trousers, take out my penis, and quietly manipulate it until I fire my gob into my wastebasket. The knowledge that I am wearing crotchless pantyhose, and that my visitor doesn't know what I'm doing, makes my orgasm all the more exciting, as does the knowledge that I must be still so as to keep it a secret.
So far, I've never been caught. I almost wish I would be.