[Part 1](https://www.reddit.com/r/eroticliterature/comments/grxnn0/my_wifes_sister_mf/)
Adrianne headed up the stairs extremely giddy with excitement. She couldn’t tell what had come over, but it was so hot. She tried masturbating in her room, but it wasn’t the same. She had forgotten to grab her vibrator from her room. When Sylvia and Erick came over, they slept in her bedroom downstairs, and she took the guest bedroom upstairs.
She sighed. She wanted to go downstairs and grab the vibrator, but what if Erick and Sylvia were in there? She couldn’t embarrass herself like that. And what about Erick? She thought, “I mean, he didn’t protest and was really into it,” but she definitely crossed a line with her own sister’s man! There is no way. As an outsider, she thought Erick and Sylvia seemed happy and fulfilled. What had pushed her to do something so risky and wrong?