The Choice by Nicholas Sparks

He added cheese to another cracker. "When does your boyfriend get back to town?"
"Are we back to this topic again?"
"I'm just thinking of you. I don't want to get you in trouble."
"I appreciate your concern, but I'm a big girl. And not that it matters, but he'll be coming home on Wednesday. Why?"
"Because I've enjoyed getting to know you these last couple of days."
"And I've enjoyed getting to know you."
"But are you bummed it's coming to an end?"
"It don't have to come to an end. We can still be neighbours."
"And I'm sure your boyfriend wouldn't mind if I took you out for another motorcycle ride, or went for a picnic with you, or if you sat in the hot tub with me, right?"
The answer was obvious, and her expressions became more serious. "He probably wouldn't be too happy about it."
"So it'll be ending."
"We can still be friends."
He stared at her for a moment, then suddenly grabbed at his chest as if he'd been shot. "You really know how to hurt a guy."
"What are you talking about?"
He shook his head. "There's no such thing as being friends. Not with single men and women our age. If just doesn't work like that, unless you're talking about someone you've known for a very long time. Certainly not when it comes to strangers."
Gabby opened her mouth to respond, but there was really nothing to say.
"And besides," he went on, "I'm not sure I want to be friends."
"Why not?"
"Because most likely I'd find myself wanting more than that."