I know JUST what you mean
I love to tickle, but I love BEING tickled too!
I once had this fat girl sit on my butt, and she snaked her hands inside my shirt, and went to work on my ribs. She went on for about twenty minutes until I was out of breath. I caught my breath, began to thank her, and she started tickling me again! (I had forgotten that I told her to ignore all pleas, and continue tickling for five minutes AFTER I said the safe-word - which I hadn't done). Finally, I gave the safe-word, and she continued for TEN minutes.
Another time I finally got tied up, but she was too gentle and didn't go long enough - still, it was really fun.
Start out with a one-minute tickle, then work your way up - it's great, trust me.