I have accidentally had extras.
My first real massage, and I think the gal was new, early 20s, very odd-looking, but I LOVE that, super tiny body shape. (I was around the same age at the time.)
When she massaged my back, she leaned over my head, and I felt her tiny yet very soft breasts pressing into the back of my head. She had a stretchy-type bra on, so it felt like she wasn't wearing anything. It was an incredible feeling that I remember to this day.
Later, she massaged my arms, and she rested my hand on her rear-end because my arm was so long. I didn't know if I should squeeze or not, so I just let me hand rest there. (I talked to a massage-friend of mine about it, and I guess that's normal to do, but typically you put their hands on your hips, not rear-end, but given how tiny she was, her hip might have been too close for my long arms, I guess.)
Then, as I was turning over, she accidentally exposed me a bit. She was super embarrassed, but I said it's fine, so she took another peek, but on purpose! Then she smiled from ear to ear for the rest of the massage.
The few massages I have had since over the years then were all absolutely terrible! I did try to find a place on a road trip once, but they were literally shut down the week before for offering extras!