My Sister the Serial Killer by Oyinkan Braithwaite

Korede is the responsible sister, everything her sister Ayoola is not. Korede is practical, methodical, sensible, practical, and plain, while Ayoola is flighty and charming to everyone she meets. She also has the unfortunate habit of killing off her boyfriends, leaving Korede to help conceal her crimes and literally clean up the mess.

When Ayoola sets her sights on a handsome doctor at the hospital where Korede works (perhaps it's also not a coincidence that Korede has had a secret crush on him for years) Korede must reckon with what her sister has become, and just how far she is willing to go to protect her.

This book is full of dark humor and packs a punch, despite only having 220 pages in it. You'll want to keep turning the pages of this addictively unique thriller, and it will stay with you long after you've turned the last page.