My son's woman has a thing for me?

My eldest son Benjamin, who is 15 has a girlfriend who he has been with for 5 years, recently since she has started to reach puberty I've noticed her giving me the eye and making inappropriate comments like "Your wife is lucky to have you" and "I hope I have a man like you when I grow up", I am a Christian man and am devoted to my wife, I have absolutely no interest in her, I have told her to 'simmer down lil' lady' on a few occasions, but I don't know what to do next? raise it with my son?...It's starting to upset my woman.