Cake by Sandra Newman
Fleeing to London from the spectacular collapse of her family, Tanya builds a business and begins finally to conquer her addiction to sex. Then the gorgeous, chaotic, ex-prostitute Eleanor enters her life and her home. El is an addict with a history of violence - and possibly a great artist. And sex with a woman can't be sex addiction, can it? Tanya decides that what El needs is a safe haven. It is a decision she comes to regret because, in Sandra Newman's rollercoaster world, murder begins at home.