She kept him 'in suspense' [=waiting anxiously] for two whole days before she agreed to marry him.
I don't know who won and 'the suspense is killing me'. [=I am very anxious to know who won]
The 'suspense' builds as the story progresses.
(..) Well, I came to talk about Danny, but we don't have to do that right now. I brought you some books. Well, what about him? You know? Don't keep me in suspense. He's headed right where you are. Oh, man, you know what? My mother already laid this trip on me, man. Danny's not my responsibility. (..)1998 American History X