I remember visting my brother a log time ago, and looking through a couple nudie mags that he had lying around. One of them was definitely "Penhouse." There was an article in Penhouse Forum about a female personal trainer who said she was extremely ticklish and all the male trainers knew about it. They would all sneak tickles in during the day, and they nearly drove her carzy tickling her all day. Finally, she said they "captured" her after hours, tied her to one of the machines, and tickled her upper body without mercy. I think she described getting her armpits and ribs tickled by two or three guys. When the tickling was over, she said "you have a lot of nerve!" One of the guys replied, "Next time, it will be your feet!"
I've always remembered reading that tickle story because it was the first mainstream tickle reference that I ever came across, other mentions on tickling on TV shows.
Is that the article you're talking about?