One of my wife's friends is a lesbian.  One day we got to talking and I asked her did she ever wonder what it would be like to have children.  She said it was the one thing she regretted about her sexual orientation, that she might never be a Mother.

She's a good-looking lady, and I said slyly that if she ever wanted to be impregnated, I'd be happy to help out, purely altruistically.

She shot me a death-ray look, and told me with a curling lip that if she ever decided to reproduce, it would be by artificial insemination.

"No problem," I said, "If you want artificial, I'll tell you I love you."