Open Question: My daughter has a tickling fetish? Is this as crazy as it sounds?

[feedcrawler]

She is 14 turning 15 and has a tickling fetish and begs me to tickle her and tickle me and she tortures my other daughter who is 4 and she tickles her till she screams and I try to stop it but she does it behind my back. She won't admit her obsession but I did catch her online watching ''Tickle torture'' clips on youtube of people bound and tickled. I asked her what she wants for her birthday and she said '' For you to tie me up and tickle my feet''It is getting creepy and her sister hates tickling but can't make her stop and I have banned her from tickling her sister but she won't stop because she is obsessed with it.Maybe she likes the idea of torture and this is the way she likes it. Does she need to see a doctor for this? It is very weird but is it normal and should I expect it?

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