It's super common actually, and i don't see anything weird about that. It's really not different than being into how a person looks, or how they feel, or how their voice sounds. A lot of girls like to sniff me when we have sex, and there's some people whose smell just makes me weak in the knees in the best way possible. I always smell the pillowcase after i've had my gal pal over, i know a lot of girls who sleep in a used t-shirt of their partner when they're not around specifically because it smells like them, i think armpits are also the most common kink on German grindr etc., it's really not unusual.