Some call it a Liverpool or Glasgow kiss. In boxing matches, it has been described as putting the nut in.
Whatever the words you use, head butting is an unacceptable practice, even more so when you are Alan Pardew, the manager of English Premier League club, Newcastle United.
Already a subscriber? Log in.
Win a prize this Mother's Day by subscribing to our annual plan now! T&C applies.
Cancel anytime. No ads. Auto-renewal. Unlimited access to the web and app. Personalised features. Members rewards.
Follow us on our official WhatsApp channel for breaking news alerts and key updates!