An anonymous source close to Simpson said the celebrity couple was planning a romantic Valentine's Day celebration together to recognize their love for one another, People.com reported Friday.
"They're very much looking forward to spending Valentine's Day together," the source said. "(Tony) is the nicest guy. He adores her. They are so in love with each other."
Simpson was to open for Rascal Flatts in Rochester, N.Y., Saturday.
The pop star, who has been dabbling in country music recently, dedicated a song to Romo Thursday while performing at New York's Madison Square Garden, People.com said.
"There is something about being in love, right?" Simpson told audience members while performing "You're My Sunday" in honor of the NFL star. "It just makes you appreciate every day, right? ... That's kinda how I feel right now."