I have this crazy idea for a storyline. So my character and your character dated back in high school. They broke up right before he left for college only to meet his current wife. Turn the page a few years later and my character looks completely different. She answers an ad for nanny from your character and starts working for them.
She ends up seducing your character into an affair. He enjoys sleeping with them both. But as time passes sex with the wife gets less and less. And sex with the sitter becomes more and more. Eventually thebabysitter ends up pregnant by him and has to lie yo jot be found out.