Sons’ Shared Slave

A cold, emotionally distant mother (Sylvia, 43) has lived in a loveless, sexless marriage with her (likely gay) husband. Her youngest son John (22, recent graduate) finds her crying one day, comforts her, and their relationship quickly turns sexual. Sylvia discovers passion and love for the first time.
Her older son Craig (23) already has a dominant/submissive marriage with his wife Gretchen. When he learns John is sleeping with their mother, Craig forces Sylvia into submission too — turning her into his “slave” alongside his wife.
The story ends with the entire family (minus the father) fully embracing a highly kinky, incestuous dynamic: both sons share their mother sexually, the two women become submissive “pets,” and they engage in group sex, double penetration, face-sitting, bukkake-style scenes, public teasing, etc. Sylvia transforms from an emotionally shut-down woman into a willing, lustful submissive who loves being used by both her sons.