This one's by Charles Ott. Check out his book Floor of the World on Amazon.
“You’re smart and sweet,” Thomas said. “I’ve always admired you. One thing stops me – you talk too much. If that sounds trivial, it’s not: if you and I were married, I’d be snapping at you after three weeks.”
Olivia smiled. “Married? You haven’t even asked me out for dinner and a show yet.”
“And I can’t take even that first step for a doomed romance. Olivia, can you change?”
“What will you give up in return? What’s valuable enough to be your sacrifice?”
He was silent a while. “I know the answer. The only thing valuable enough is … you.”