you can't expect (one) to believe (something)

you can't expect (one) to believe (something)

What you are saying is absolutely ridiculous or wholly unbelievable, and there is no way one will believe it. Try giving a more straightforward excuse as to why you can't come into work today. You can't expect your boss to believe such a bizarre story. A: "I finished my homework, mowed the lawn, did the dishes, and cleaned my room!" B: "In the span of an hour? Ha! You can't really expect me to believe that, can you?"
See also: believe, expect
Farlex Dictionary of Idioms.

You can't expect me to believe that.

 and You don't expect me to believe that.
That is so outrageous that no one could believe it. Bill: My father is running for president. Bob: You can't expect me to believe that. Jane: Everyone in our family has one extra toe. Mary: You don't expect me to believe that!
See also: believe, expect, that
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • You can't expect me to believe that
  • you don't expect (one) to believe (something)
  • you wouldn't read about it
  • come again
  • come again?
  • cockamamie
  • GMAB
  • shoot straight
  • shoot square
  • I can't believe it/that/this