Liven Up Your Marriage Day!
Embark on a low-speed freeway chase. Pretend that your wife killed your mistress and you. So the real you is dead. But on this low-speed freeway chase, you're one of the policemen who is chasing her. So just drive one car length behind her on the freeway for around 170 miles.
She'll pull off in San Diego. Tell her to get out of her car with her hands up.
She'll say, "But officer, isn't there some way we can work this out?"
Tell her you'll forget all about her having killed her husband and his mistress if she has sex with you in the front seat of her car. She'll say deal.
The sex will be some of the best ever. Nothing turns you on more than having sex with your wife while she's pretending to have sex with a policeman in exchange for him letting her get away with having murdered you. You love the thought of being dead while your wife has sex with cops.
You don't like to step out of the role-play, but she said ahead of time that you would be allowed one little slip. So at the height of arousal, just before you both come, you whisper into her ear, "I'm so lucky to have you." Then you go back to being Officer Schwartz and fuck her until she loses her voice.
Happy Liven Up Your Marriage Day!