Name of story - fiancée tested by her fiancé and has the best sex of her life: ends with driving away laughing AND crying

[TheAmbidextrousLeftHander]

What I can recall:

• girl is going to be married
• ?the week before she’s at a bar
• Gets picked up by a good looking guy who relays that he has lost his cheating girlfriend
• She has one last fling - greatest sexual experience of her life
• Then she returns home to find her fuming fiancé
• Turns out he set it up as a test, revealing things about the testers contrived story
• He lets her know the wedding is off
• She thanks him for the best sexual experience of her life
• While driving away she is laughing and crying in equal measure

This was The Ambidextrous Lefthander