Incentive

"OK, here's the deal," I said. "Lisa is a horny, submissive bisexual. Edwin, you are sexually dominant, and your wife...what's your name?"

"Amanda," said the wife looking a bit shocked.

"Amanda, you are sexually submissive to your husband, but you have longed to sexually dominate another woman as you are also bisexual."

"Edwin, you'd love to have a three way with a woman both you and your wife dominate, and Lisa gets off and being dominated, even with some light humiliation thrown in, so what would it take for Lisa here to seal the deal?"

Edwin smiled. A bulge grew in his pants. Lisa started to blush, and her chest started to heave as did Amanda's. Edwin cocked an eyebrow.