Only my therapist knows about my tickling fetish. I've talked about it with her, but I'm a little too shy to go into much detail. I don't feel comfortable talking about it with my friends, although they are all very open (sometimes too open!) about their own kinks and quirks.
My mom knows I'm ticklish and sometimes will "sneak attack" me in a playful way, but she has no clue about the depth of my tickle-mania. I can't imagine talking to her about it. She's very conservative. (I can't even talk to her about vanilla sex, let alone fetishes.) She almost caught me recently, however. I'm planning a session with my online tickle buddy, and I bought some rope as part of my preparations. When I walked in the door she saw the rope peeking out of my shopping bag and she asked me what I had gotten it for (did I mention that she is very, very nosy?). I stammered some kind of excuse and she left me alone, but I can tell she's suspicious.