Your wife's and her sibling have always been rivals, and now it's spilled over onto you. There's nothing more that your wife's step-sis would love more than to get you to cheat on your wife...with HER. She invades your bathroom while step-sis is napping and seduces you into the best blowjob of your life. Mindblowing orgasm, and she lets you cum in her mouth - your wife never does that. That felt fantastic, and now you can't wait to fuck your step-sister-in-law!