The 73-year-old Hollywood icon has been dating the American Idol producer, 64, for more than a month and is said to be smitten with the Brit, sources tell the Sunday Express.
An insider explains, "Raquel finds Nigel fascinating and an absolute English gentleman. Even though she is almost 10 years older than him, she stills looks great and Nigel is so smitten he seems to almost worship the ground she walks on.
"The chemistry between them is so strong, they are just going with it. Raquel's fully aware that age might not be on her or Nigel's side. But I haven't seen her as happy as she is with him for more years than I care to remember."
Lythgoe most recently dated Elvis Presley's ex-wife Priscilla, while The One Million Years B.C. beauty has four failed marriages behind her.