YMMV / Inside No 9 S 4 E 4 To Have And To Hold

• Complete Monster: Adrian is the emotionally abusive husband of heroine Harriet. Belittling and controlling Harriet every chance he gets, Adrian has a dark secret: years ago, Adrian kidnapped the cleaning woman Agnes and keeps her imprisoned where he tortures, beats, and rapes her, having fathered a son from this. Said son, Levi, is kept imprisoned, beaten, and abused, with Adrian even raping Agnes in front of him.
• Moral Event Horizon: The Reveal that Adrian is keeping Agnes chained up in the basement as a Sex Slave.