i have a female friend who is willing to try most anything. on 6/7 occasions i have tied her to a bed or to homemade stocks and tickled her feet to the point of exhaustion. at first it would take up to 3 and 1/2 minutes to reach exhaustion but as time has gone by this point is reached in about 2 mins. The screaming reaches the same level but as she says just when she reaches the point when she cant take any more her feet go numb.She is then in a state of semi exhaustion and total relax. The thought of going through the relentless tickling panicks her but the end result is fascinating. it makes good watching as it is captured on video. any one know how to prolong the tickling time. the method used is stockinged feet and bare fingers and of course total lack of movement