Hello, Mr Thomas Grey

Rachel Stuart never thinks that the story of a novel could happen to her in just one day. She found her fiance, who has been engaged to her and is going to get married in two months, cheated on her.
She drives to a bar to drown her sorrow in alcohol. She sleeps with a high quality man and gets the marriage certificate with him, even though she knows him for less than one day. This man says his name is Thomas Grey. Why this name sounds so familiar to her?