Professor Andre Levin is about to marry his 3rd wife. Naturally, his first and second wives will help him greet her and assist her in satisfying him. After all, that's what a harem is for, right? This is a story set in a future where plural marriage is commonplace.
Vault 76 has 'Programs' that everyone is issued and must follow for the good of the vault. Many of these 'Programs' are sexual in nature, but residents opt into them willingly. Samantha opts in, wanting to be an asset to the vault. This leads her down a path she never imagined, taking every wrong turn possible. Some points in this story jump between scenes rapidly, hopefully they aren't too bad to follow along with :)
Bill and Missy have just married and when Missy asks Bill to fuck her and give her a new baby, they succeed. Now, three months into her pregnancy, Missy is starting to show and Bill finds her so sexy he can't keep from fucking her. They both enjoy their new state of expectancy.