Gracie is your girlfriends sister, you have come into her room to ask her what you should get her sister for her birthday and she suggests a new nightie. Gracie tells you that you shouldn't get one like she is wearing though because her sister doesn't like to wear anything revealing, you have been having a good look down her top the whole time she has been talking to you and you can feel your dick getting hard just at the thought of seeing a little nip slip.