Stories from Nothing: The Proposal

Catalyst: 
A woman was proposed to at a table near my boss. While the husband was beaming, my boss and her friend were weeping and ordering champagne for these strangers, the bride-to-be did not look too enthused.

The Story:
The ride home was especially quiet that night. Mark was at the wheel and he was smiling into the horizon. He couldn't wait to get his new fiancee home. Fiancee. Man, he couldn't believe his luck. She had really said yes. He was so happy. The people next to them had bought them champagne, on top of the champagne he'd already ordered for the special occasion. He'd been planning this for weeks.
"You're awfully quiet," he said, turning to Brandi in the next seat. She was staring out of her window, looking at the long string of trees passing by on the side of the road. "How are you?"
"Jesus."
"What?" he said, his brow furrowing. "What's wrong?"
"This."
"This?"
"Yes! This!"
"I don't follow." A well of concern washed around in his brain.
"Of course you don't."
"Brandi, honey, what's wrong?"
They stopped at a red light, sitting there, the left blinker flashing on and off. Tick, tack, tick, tack, in a rhythm that never seemed to end.
"I don't want to marry you."
"What?"
"I don't want," she looked at him, now. Her blue eyes were cold. "To marry you."
"But," Mark felt his whole body open up beneath him in an empty zenith, "but then why did you say yes?"
"Are you kidding me?"
Mark only looked at Brandi, tears welling. She sighed.
"How could I say no?" she said. "We're in a restaurant full of people watching!"
"So?" Mark pushed the car forward. "You could have been honest with me."
"Oh really? And then, what? Said no and quietly slipped out of the restaurant, a carpet of silence following me as people say in hushed tones, 'how could she say no? He looks so lovely'!"
"So instead--"
"So instead," she cut him off, "I pretended to say yes so I could get out of there in one piece."
"Brandi, I--"
"Take me home," she was talking as if he wasn't there. "I'll come get my stuff in the morning."
The wind outside was colder than usual for summer.