In high school at Physed when it was time to swim in the pool, all the boys had to swim naked. I remember leaving to locker room heading for the pool in my swim trunks, the teacher told me to take of my trunks. I was a late developer and I was looking at bodies that were not, they had hair, I did not, their balls had descended, mine had not. I remember some teasing that went on.
So that experience made me very self conscious of my body and did not flaunt it to girls either.
At some point a girl told me I was bigger then most which brought me out of my shell and Ii started hooking up with girls. Later in life when I was in my 60's some 15 years ago, I and my girlfriend at the time were attending a local swing club.
The closest I got to a cock was during a double vagina where I wore a condom and her husband did not.
Being of reasonable size 8.5"x6"uc, I got invited (without my then girlfriend) to a couples house for a hot tub and play.
I arrived, with in minutes we were all in the hot tub naked, I was on one side and the husband and wife was on the other side of the tub.
The pump was roaring causing a lot of bubbles to be present which obscured underwater vision.
I remember feel a hand around my cock and noted to myself the she had a strong grip, it took about 5 seconds to realize it was his hand and not hers.
That evening I lost my anal virginity to her husband and I had my first male penetration of a male's ass.
Love the smiles.