Whats the name of this old movie?

it starts with this married couple talking to there friend about her husband who disappeared, then later in the movie the husband shows up at the couples apartment, but he says hes not the friend they knew, hes a spy who had plastic surgery to look like him. so they go to a restaurant where he explains he has to pretend to be this guy, and he does this trick where he flips a spoon into a cup. he says “i understand your real friend used to do that a lot” and the wife replies “yes but he would always miss” “oh il have to make a note of that” . At one point he has to convince “his” wife, cause if he can convince her he can convince anyone, then i don’t remember much except it ends with them zooming in on the spoon, and it flips itself into the cup, showing it was pre rigged to work or something