When I was in my early 20's I lived in a small apartment owned by 2 middle-aged sisters. The one drawback to this apartment was that it didn't have a private shower. The shower was in the basement in the same room as the washer and dryer. One evening I came home from work grabbed a towel and went to shower. I hung my towel and clothes on the hooks provided walked across the room, about 20 feet and started to shower.
While I was showering I didn't hear the 2 sisters enter the room. They sat on the bench by the door and watched me shower through the translucent shower curtain. When I finished my shower there they sat between my towel and me. I stood there surprised and somewhat embarrassed. My dick rapidly hardened and the foreskin retracted totally exposing the head of my dick. I reached for my towel and one of the sisters said, 'Wait a minute I'm not finished looking,' as she reached out with her small soft hand and started stroking my hard dick.
The other sister chimed in and said, 'If you want your towel and clothes back you will masturbate for us.'
I agreed to masturbate for them if they would remove their clothes. They both stripped. First exposing their small breast with very hard nipples. Then removing their remaining clothing. Both had very thin pubic hair and their clits protruded like little dicks. One of the sisters said, 'Ok now it is your turn.' I started stroking slowly at first and increasing speed as they egged me on. I shot an exceptional load that day, high volume and high pressure.
In the following months we did the same thing a number of times, whit some changes.