The definition of sour grapes is:
(idiom) when someone says negative things about something because they can’t have it
A: Do you like my new car? It’s a Honda Civic.
B: It’s okay.
A: You don’t like it?
B: It’s fine. Whatever.
A: That sounds like sour grapes.
When Marty told Ahmad about his vacation plans to China, Ahmad had sour grapes and told him he didn’t like China.
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