Searching: Cop cheats on wife, who is a murderer called Kitty

[TheSpaceBagel]

Gosh, it's been so long since I read it but it was so good. The cop is cheating on and neglecting his wife. She is unknowingly murdering cheating husbands when she's 'sleeping". It's so specific but I cannot, for the life of me, find it. She called herself Kitty if I recall. Help would be appreciated! (٭′ᵕુ‵)ુ(ૂ′ᵕ‵ॢං)