I've been sniffing my sister's underwear
Why do you sniff her underwear?
I love them, their beauty is breath-taking
Some kinks are okay but sniffing your sister's underwear is not. In fact you shouldn't sniff anybody's underwear. People will think that you are a pervert.
I'm a different person.
You should stop sniffing your sister's underwear and talk to a therapist. It is not normal or okay to be attracted to your siblings, so you need to talk to someone about why you feel this way.