You make me laugh!

you make me laugh

A humorous or sarcastic response to a statement that one thinks is ridiculous or highly improbable, as if it were a joke. A: "Monica is coming to the meeting tonight, right?" B: "Ha, you make me laugh—she hasn't been to one all year." You want to become a lawyer? You, who used to steal money from your parents to buy weed? You make me laugh.
See also: laugh, make
Farlex Dictionary of Idioms.

You make me laugh!

Inf. Fig. What you said is totally ridiculous.; You are totally ridiculous. (Compare this with Don't make me laugh!) Bill: I have this plan to make electricity from garbage. Sally: What a dumb idea! You make me laugh! Bill: I'm really sorry. Give me another chance. I'll never do it again! Jane: You make me laugh!
See also: make
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • tell me something I don't know
  • (hardy) har har
  • sarcasm is the lowest form of wit
  • tell me another
  • tell me another one
  • Tell me another one!
  • Tell me another!
  • FTFY
  • IFTFY
  • IFYPFY