It depends on what you term as masturbation.......but if we discussed it then this thread will get moved to the Sheets forum.......so we have to move on!!
1. Delawh_re - I'll let you guess the missing letter; meant lovingly cuz you know I dig ya.
2. The Gym Tramp
3. Thong-wearing Gym Tramp
4. <Movie Star> Body Double - Insert any famous babe with a knockout body.