How did you do that?

[rebbonk]

During a recent vacation in Las Vegas, a man went to see a popular magic show starring Derren Brown. After one especially amazing feat, a man from the back of the theater yelled, "How'd you do that?"

"I could tell you, sir", Brown answered, "But then I'd have to kill you."

After a short pause, the man yelled back, "Ok, then...

Spoiler:

just tell my wife!"