He convinces her that she wants to have a threesome.

"I've been thinking about why we separated," Matthew says on the drive home, "and it all stems from your suppressed desires, doesn't it."

"Yes, it must," she nods and Matthew can barely believe how easy this is.

"For example," he continues, barely suppressing a shit-eating grin, "when you got so mad at me when you found those lesbian porn videos on my computer--we both know that you were really mad at yourself because of your own desires to be with those women as well as men?"

"I...I never realized it before, but that must be true. Wow, my whole life I never realized I was bisexual until just this moment!"

"You know, it might save our marriage if we explored this new side of you together!"

"But I don't want to save our marriage, I've been happier since..."

"Honey, that's just your sexual repression talking--you thought you could never fully explore all your kinky sexual urges--like your bisexuality, and your desire to be dominated--from within marriage. But that's not true! I'd be happy to help you open up sexually--even if it means I have to watch you have sex with other women. Hell, I'll even have sex with other women with you, even though I don't want anyone but you, since it will help you feel more comfortable."

"Oh Matthew! You're so giving and generous. You're absolutely right, I do want to have sex with other women and be dominated sexually--will you really help me?"

"Honey, I'd love to. Let's put an ad on Craigslist as soon as we get home."