Kyle had asked Laine to marry him not once, but twice which at least should have argued sincerity on his part. Or, perhaps it was just determination- if he was serious, wouldn't he have told her that he loved her?
Seven years ago, Laine would have had no doubts. But then the affair had ended in bitterness and anguish, and she hadn't seen Kyle since. So how could she be certain that he wasn't just out to get his revenge?