Sister gave me an armpit fetish
My sister is 2.5 years older than me so she could drive before I could. I would have to beg her to take me places and one day she told me I had to smell her armpits to get a ride. It wasn't sexual to her, just a way she thought she could embarrass me and prove she was in control. But I got turned on with my face buried in there smelling her. I never mentioned it and had to hide my boner. She started making me lick them too and I began to crave it. After a few weeks I would come in and just start licking her armpits instead of asking and she'd sit there like a queen and finally ask where I needed a ride.
I think your sister did think it was sexual. Her pussy probably got wet whenever you licked her armpits. I bet she lightly fondles her armpits with her fingertips while she masturbated and thinks of you.
My sister gave me a heel fetish
Licking armpits is so hot