My Sister, the Serial Killer by Oyinkan Braithwaite (2018)

“Ayoola summons me with these words—Korede, I killed him. I'd hoped I would never hear those words again."

Fantastic short novel about Korede and her sister Ayoola, the serial killer of the title, who keeps murdering her boyfriends. Korede is left to clean up the messes. When Ayoola starts to date Korede's longtime crush, things get especially complicated and messy. SO readable, engaging, and gripping, and the setting of Lagos is vivid and fascinating. 

Looking forward to Treasure and The Baby Is Mine, out in 2020.