Don't Cum... Stop!

Your step-sister is sitting on the stairs waiting for her taxi to arrive; she's about to go on a date and you're feeling slightly jealous. You've always had a bit of a crush on her, and she's looking particularly lovely this evening with her dress, suspenders, stockings, and heels. Aston can see your horny eye wandering up her dress and notices the bulge in your pants... but she seems to be enjoying the attention...