I think my dog is a ....?

so my dog likes to take mine and my friends underwear, drag them into the living room, and steadily lick the crotch part and sit there with her face buried into it until my dad yells at me to go pick them up. not that im leaving my dirty underwear laying around, theyre in the hamper she just finds a way to get them and annihilate them. i just want to know what the attraction is. and no im not a gross person.