A Christina Cooper Story This first part of the Christina Cooper story is all about setting up the character of Christina, understanding who she is and where she comes from. It does not contain a sex scene as such since that story is before she was 18 years. You can skip it and move on to the other parts, but you'll miss the character's background, so it may be harder to follow the other parts of the story.
Jenna is afraid that her husband is losing interest in her, so she enrolls in a "Wife Boot Camp" to become a better wife and lover. At the "Boot Camp" she is under the control of two teenage girls who act as her "drill sergeants." The drill sergeants fuck Jenna nightly with a strapon cock, teaching her new ways of satisfying her husband. But the situation becomes complicated when Jenna falls in love with her 14-year-old drill sergeant who fucks her better than her husband ever did.
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 :)