Relatively Speaking

The "parents" do not at first understand him correctly; for Ginny's parents are really in Australia, and she has come not to visit parents but to tell her former employer and lover that all is over between them: she is going to marry Greg. The "father" finds himself trapped between the two women, and has to play the role of father

But he does not give up easily. He makes a deal with Greg to take his daughter on a tour of the continent as a wedding present. It is at this point that "mother" is given the old pair of slippers left under Ginny's bed by her "father," and begins to put two and two together. After the lovers leave and the "parents" are again alone, "father" discovers the slippers, staunchly declares they are not his, and begins to inquire what his wife is doing with the slippers of another man. But this is one secret "mother" will not divulge

A British hit, with reviews describing it as "deliciously heady," "a near miracle," and provoking "the proverbial gales of laughter"