Little to add to my colleagues' thoughts, except that your friend will have to endure the ludicrous stereotyping snide comments that they will both get. If a man dates a younger woman, he is a 'lucky stud', and if a woman dates a younger man she is a 'cradle snatcher' - it's part of the ritual people go through because the lack the wit and insight to realise that their comments are a) very old, and b) weren't true, or indeed amusing, the first time! Tell your friends to grit their teeth and smile! Other than that, they should enjoy their relationship together, and remember, there;s only one thing worse than being talked about, and that's NOT being talked about!