An earlier story in this series/setting ("Melody's Captivity") is on this
token site (ie not free). And anyway it's a bondage story with only a very brief tickling scene.
A later story in this series/setting ("A Ticklish Deception") was my response to Invisible Inks "chopped liver writing contest." But I'm sure you've already seen that one.
More stories in this series are in my muse's inbox, but my muse isn't the most prompt or cooperative imaginary creative being.