My sister, the serial killer

Korede, is in love with a handsome doctor at the Nigerian hospital where she works, but can't bring herself to pursue him because her sister, Ayoola, has a habit of killing her boyfriends--three so far--which means she's officially a serial killer. But the doctor then asks Korede for Ayoola's number, and Korede must decide how far she's willing to go to protect her sister.