She looks wonderful.

Your sister's more reserved appearance isn't lowering your urge to bend her over and slut fuck her ass, but with her body you realize that urge is probably never gonna go away. You hug her and press her huge soft tits close to your chest and say "You look perfect." You give your sister a good long kiss which she is more than eager to reciprocate.

You hear a knocking noise and part from your sister's lips to see your mother standing in the doorway, she is wearing booty shorts and a cut off t-shirt that gives a wonderful view of her expansive under boob. She looks your sister who is still clinging to your chest up and down, and giggles "Well look at this all it took was your brother's fat cock to turn you into a proper lady." Your sister gives her a mocking glare and your mother continues "So am I driving you or are you two taking the train?"