Here We Go Round the Mulberry Bush (1968)

Frustrated that he still hasn't lost his virginity, teenage grocery store delivery boy Jamie McGregor (Barry Evans) appeals to Spike (Christopher Timothy), an older ladies' man, for advice. After failing to seal the deal with several local girls because of his working class mannerisms and a paralyzing case of teenage self-doubt, Jamie struggles to get the attention of Mary Gloucester (Judy Geeson), a beautiful classmate who doesn't seem to know he even exists.