When I was 13 i would go home straight from school with my friend to her place for tea, we would often go up to her room to chill out before our food was ready, her dog would come up with us. He was always humping our legs, we would laugh our heads off, well one day we were play fighting him and he ended up between my legs, he was sniffing and licking my underwear, I managed to push him away. i was embarrassed but also turned on, my freind said hes always doing that to me too, hes so randy. That was the start of my interest for me.