I'm going to a lecture

The man was in no shape to drive, so he wisely left his car parked and walked home. As he was walking unsteadily along, he was stopped by a policeman."What are you doing out here at 2 A.

M.

?" said the officer."I'm going to a lecture." the man said."And who is going to give a lecture at this hour?" the cop asked."My wife." said the man.