You're minding your own business, happily playing with toys, when your Big Sister storms in and starts teasing you for being so immature. She tells you that she stopped wearing underwear and asks if you want to see. Big Sis flashes her bare tits and pussy, then demands to see your cock in return. She asks if you've started jerking off yet, then suggests the two of you do it together. Alternatively mocking and encouraging, she tells you how to stroke it for her while she fingers her pussy and talks about what you're doing together. Get yourself off with your Big Sis - then hurry up and get dressed before mom and dad get home!