My Sister, the Serial Killer

What wouldn't you do for family?

What you see is what you get with this novel’s title - the main character’s sister, Ayoola, is a serial killer, killing each of her boyfriends in turn, while the long-suffering main character, Korede, is stuck cleaning up the mess. Korede is tiredly tolerant of her sister’s actions, at least until Ayoola begins dating a doctor at the hospital where Korede works. 
I really enjoyed listening to this (surprisingly funny) novel about how far you will, or won't, go for your family.