Your sister is very horny and wants to fuck you and be sprayed by your cum, so she teases you about it. She teases you with barely keeping herself covered for the duration of this exchange getting to admit your desires too as you stroke and play. She lets you go inside of her a small bit, but you cant look! until she deems you worthy of fulling seeing her naked (you were always worthy but she likes the game) and you end up cumming on her breasts.