Want to Share my Wife

We are a couple that has been married for twenty-three years. We have three kids and within the last five years or so, our sexual life has stopped. I noticed my wife was interested in younger black men and I have asked her to date other men if that what she likes. She gets very defensive when I say this. I want to see her have a lover, but I don't know what to do to encourage her.

— Sam, 58