This is a pun.
That won't work.
バカだ。
大袈裟だな。
You're overreacting.
That's crazy.
冗談ですよ。
冗談ですよ。
冗談ですよ。
It is a piece of cake.
〈何とも思わない〉 I don't care at all.
I don't care [give] a damn.
冗談です。
がっかりですね。
I'm kidding.
That's a joke.
I was just joking.
悪意でした.