I'm not really into tickling a girl until she pees, but it did happen to me once. I've actually posted this story before, on what thread I can't remember. Anyway, me and my girlfriend at the time were at my best friend's apartment, and his girlfriend was there too. My friend's girlfriend had went out for a cig run, and when she came back, me, my girlfriend, and my friend were all sitting on her couch, and her cat had gotten on the chair and fell asleep, so she had no place to sit. She said "where am I supposed to sit?", and we all just gave her a shrug. She then proceeded to lay down across all three of us on the couch. My friend then got an evil look in his eye. He was sitting at her feet, I was in the middle, and my girlfriend was on the other end of the couch. My friend grabbed her bare feet and started tickling them, and she started bucking madly. She let out a desperate "He-Hell-Elppp!" My friend then said, "You heard here, give me a hand!" As his girlfriend let out a "NOOOOOOOOO!", my girlfriend held her arms over her head with one hand and was tickling her armpits with the other, and I raised up her shirt a little bit and started tickling her tummy. I guess it was too much for her, because about 30 seconds later she peed all over me! She was a little embarassed and we were both a little wet, but fortunately she's pretty good spirited and she laughed it off the best she could. Sorry that story was so long, I just thought I'd share it!