Only Slightly Used

Dave and Mia had been married for eight years, together even longer. It was only natural that their sex life had suffered after all this time. There just wasn't any zing to it anymore! Trying different ideas to liven up their nighttime fun, they had gotten excited over certain fantasies. Their favorite, being Mia sleeping with another man. She really enjoyed the illicit images it produced. That is, she did until Dave wanted to take the fantasy further.
He wanted her to do it for real!Violently opposed to the idea at first, Mia began to slowly warm to the idea. Taking the advice of her best friend and confidant, Mia starts to spread her wings. Attending the regular Friday night after-work bash, wearing more revealing clothing, dancing with another man. Each step leading her closer to breaking her marriage vows. Vows she'd sworn to keep. Dave's birthday was coming up shortly, and his one request was for her to fulfill his fantasy.
To have sex with another man! Well, there was that cute guy in IT that she had fantasized about. Could she, would she? And, if she really did grant his fantasy, what then.