Male "donor" to a friend?

[CookieMike]

For reasons that hit shockingly close to home, would anyone be interested play a woman's who's been trying to get pregnant, but for whatever reason her husband is infertile. They've come to terms with this, and have been looking into adoption; but the wife knows her friend's husband has gotten her knocked up every time she's mentioned trying and kinda looks like her husbanded. So maybe he could fill the role of a sperm donor that they're able to keep on the DL if everyone agrees?

Bring your own kinks and ages and limits to this premise. I'd love to hear whatever idea for a twist on this you have.

Also would be interested in the reverse. Where the wife can't get pregnant anymore, but she wants one more. Maybe the babysitter could be the solution?