While your sister has been at cheerleading camp she's been preparing something special for you. She wanted to get back at you for always sticking your dirty boy socks in her face, so she has been wearing the same thong all summer to make it nice and smelly and get you back. She sticks her ass in your face and pulls down her yoga leggings and the smell of the super dirty thong hits you in the face. Instead of being disgusted like she hoped, you get an erection! She notices and teases you for a second, but then admits that maybe she did enjoy wearing her stinky panties for herself, and she was kind of hoping that you would be into it too. She encourages you to smell them, while she tells you about all the adventures this thong has gone through this summer. Then she takes the thong off and asks you to smell her dirty ass directly, while she rubs her pussy. What a naughty sister you have!