Offshoreonly.com - How is this joke?

A woman awakes during the night to find that
her husband was not in bed. She puts on her robe and goes downstairs to look for him.She finds him sitting at the kitchen table with a cup of coffee in front of him.
He appears to be in deep thought, just staring at the wall. She watches as he wiped a tear from his eye and takes a sip of his coffee. " What's the matter, dear? she whispers as she steps into the room and softly touches his shoulder.Why are you down here at this time of night? The husband looks up from his coffee, "do you remember 20 yrs ago when we were dating, and you were only 16? he ask solemnly. "yes I do" she replies. The husband paused. the words were not coming easily. "Do you remember when your father caught us in the back seat of my car making love? "Yes, I remember" said the wife lowering herself into a chair beside him.The husband continued.Do you remember he shoved the shotgun in my face and said, "Either you marry my daughter, or I'll send you to jail for 20yrs?" "I remember that too" she replied softly. He wiped another tear from his cheek and said, "I would have gotten out today."