I won't rehash the story... Everyone above has given the gist of the story. There are those who say this is unrealistic, but I beg to differ for the most part. It’s over the top but based on some truths. As a SAHM of two, I have been where Billie has (maybe it's a Georgia/Cobb County thing). I also have been with more than my share of malignant narcissists. Billie is going through post partnum and CPTSD. Brad is damaged and narcissistic, thus the ultimate bad boy. Empathic people tend to fall for their manipulations because they want to rescue and fix them.
It is Netflix/TV so they had to exaggerate. So all the characters are over the top, many are suffering from nymphomania and/or satyriasis, and are not fully fleshed out. It is borderline soft porn...but it is highly addictive.
My ONLY problem with the husband is the fact he keeps violating his wife's privacy by reading her journal. My husband (also BTW he is a fabulous husband and father like Cooper) read my diary once and he did NOT like what he read. BTW there were no tales of hot sex and exes as I am more on the asexual side, but there were probably tales of revenge that may make a serial killer blush. Journals are sacred...like your own personal therapist. Some things are NOT to be shared with anyone.
Billie needs to see a therapist. Sex should NOT be so important. However, Billie is dealing with narcissistic abuse, which is a hard thing to get over...and no one understands it if they haven't been in a toxic, narcissistic relationship.
Actually I believe the real life version of this is playing out with Chris Powell and Heidi Powell and their impeding divorce. Chris Powell strikes me as being like the husband, Cooper.