Stepsister's irresistible smelly pantyhose!

Jack is living with his stepsister Cat as long as he can remember and he does not even know she is adopted. She is a bigger girl with big feet and she loves to go for a run. A little morning jogging is the best for Cat and it turns out it's the best even for Jack. You see he is really crazy about pantyhose, stockings and nylons in general and he loves to smell them. Especially after they are worn for a long time and pretty smelly. And Cat's feet and especially pantyhose are so much smelly after her jogging that you could smell her feet even from meters away. Right now Jack and Cat are sitting in the same room and Jack can't take his eyes of her feet. He can smell those worn pantyhose and he has to have them. It's not new to either of them - Jack constantly tries to smell his stepsister's feet. And today her feet are so perfect, so irresistible he just can't control himself. He jumps at her feet and starts to smell them. Cat is annoyed by that and she still can't understand how...