This story is quite long - 38k words - but I feel like it's my absolute best story to date. These characters really lived in my head, and I'm pretty happy with how it all turned out.

Synopsis: Kathyrn (Kate) Stevens and her husband Ken decide that they are done with children and that he should get a vasectomy after her fourth pregnancy. She has issues with birth control, and neither of them likes pulling out, so this seems to be a perfect solution.

Kate falls into postpartum depression, and their sex life craters. One night, she catches Ken jerking off to porn, and a fight ensues.

The two of them start to explore porn together; Ken has a real kink for wives being fucked by men other than their husbands, and it really resonates with Kate. Eventually, they start trying this in real life.

All goes very well for a while, but they schedule a meet with a black man on a day that they know is a little risky - only, Kate has been miscalculating her cycles, making the meet much riskier than either of them realize...

Full story link at Literotica: A Taste of Kate