Use when feeling a strong blend of contradicting emotions, and you're puzzled about how to express them. After watching the bittersweet ending of the movie, I didn't know whether to laugh or cry.
Pro Tip 2/3
Unexpected Situations
Best used in scenarios that are so absurd or unusual that they trigger conflicting feelings. He painted his house rainbow colors; I didn't know whether to laugh or cry.
Pro Tip 3/3
Hyperbolic Expression
It's an exaggeration to stress the emotional confusion and isn't always taken literally. She arrived at the party in a chicken costume - I didn't know whether to laugh or cry.