Matt paced through the corridors of his mind. He couldn't find the right thing to say. That's when it hit him. He walked to the corner of Central Park, and then he saw her sitting on the tangerine picnic blanket. Her soft strawberry locks. The blush on her rosy cheeks. Evelyn. When he walked up to her she smiled. As he knelt down, he fumbled with the little black box in his pocket. Then, when he opened, it he whispered to her, "Evelyn, will you marry me?"
A grin spread across her face..."Yes."
He gently slid the diamond ring onto her slender finger and then, he kissed her. They drew each other closer. His hand found the small of her back. Then he gently caressed her cheeks. When they released their embrace, Matt said three words, "I love you."
Maybe you could try and add more suspense, particularly before he proposes and before she says yes. Good job!
Honestly speaking, I didn't like how the pacing of the plot is fast. I'm talking not only about the first paragraph but the whole story. 
Try to settle things slowly by telling us their relationship with one another. Best friends? Lovers? And it would really be awkward to read about him proposing to a woman in a middle of a street, we reader don't know about her, so portray more just a slight info about their relationship and their growing feelings towards each other. 
