Not a strong fetish but panties are a definite turn-on
Two decades ago, I was teaching at a Jr. High. A student had left a plastic bag in the classroom that contained: bra, panties and a Tampax. I couldn't identify who it belonged to but I did notice that the panties had been worn. I waited a day or two for a student to claim them and I even announced that someone had left a bag of 'personal' items in the room.
On the third day, I stuck them in my briefcase on a whim and took them home. That evening, I excitedly opened the bag intending to use them as a prop for some vigorous masturbation. I brought the crotch up to my nose and breathed in. The scent was faint, but definitely feminine and the idea that I was sniffing a pair of panties belonging to a 13 or 14-year-old student was very exciting. I stroked myself faster and faster and then placed the panties entirely over my head with the crotch right up against my nose. I took off all my clothes and leaned back on the couch and just went at it. In a minute or so I came all over myself and was quite satisfied. I did not ejaculate into the panties (isn't that a bit rude?) because I wanted no evidence as to what I had done. I took them back to class the next day and, eventually, one of my students embarrassingly asked me for the bag after school. She wasn't one of my prettiest girls, but she was young and I had masturbated with my nose in her panties.
Last year, a very cute student asked to leave her gym bag in my room throughout the semester. During my preparation period, I would always search it carefully looking for panties. The closest I came were her team shorts. Although I masturbated with them, it wasn't quite as satisfying as it would have been had she left a pair of dirty panties there. Oh well! Maybe this year.