Basically it's the power and control. I like the lee stretched out, arms over head as far as is comfortable, and wearing a sleeveless top and shorts. One might start out very softly with a fingertip stroking the underarm, and she starts to smile.......she can't help it......it's the beginning of the ".....and there's NOTHING you can do about it" syndrome. She might not be laughing at that point, but the ler is still in total control. A change in technique such as a bunch of fingertips wriggling in her armpit might cause some giggles, and then a sudden attack on her lower ribs might produce screams of laughter and thrashing. I think all of these responses are great, but the overlying theme is CONTROL......using hands (and/or toys) in various techniques to create different responses, and changing them all the time. Total control.