The ex-England captain made the promise in December and if Claudio Ranieri’s side clinch the title Lineker will be going through with the proposal in the first episode of next season’s BBC highlights programme.
Other notable pledges in sport:
1. Bernie of the Binns
Former Middlesbrough forward Bernie Slaven was forced to bare his bottom in the window of department store Binns in the town centre. The then retired Slaven made the promise on live radio in 1998 when assuming his former employers were unlikely to beat Manchester United at Old Trafford. A 3-2 win for Boro promptly followed, and Slaven’s back side - complete with scoreline - adorned the shop window. Slaven fittingly summed up the process by writing on his website: “If only I had kept my big mouth shut.”
2. Marsh’s close shave
Rodney Marsh had the honour of playing for several big teams as well as England during the 1960s and 70s. But his declaration that he would have his head shaved if Bradford managed to avoid relegation from the top flight went the wrong way in 2000. The Bantams duly survived and Marsh had his flowing locks taken off on the pitch at Valley Parade in front of the delighted Bradford fans.
3. Squeaky boot time
One failed bet clearly did not deter Marsh, who in 2013 made this Twitter prediction: “If #Stoke are ever the 1st match on MOTD I will drive to Stoke & personally clean every player’s boots....”. Sure enough, Stoke secured a thrilling 3-2 win over Chelsea and went top of the show’s line-up. In fairness, Marsh’s act helped a noble cause, as the boots cleaned were signed by Stoke’s players and auctioned for charity.
4. The return of the close shave
A decade after Marsh’s hair-razing act, Novak Djokovic and his Serbia team were getting theirs shaven - albeit in happier circumstances. The Serbians had promised to shave their heads if they secured the Davis Cup crown and, after a 3-2 win over France in December 2010, treated fans to the unique post-match celebration.
5. Getting shirty
Regular fans donning shirts of rival teams is nothing new. But Manchester United supporter Usain Bolt stepped it up a notch when in October 2015 he lost a bet with Mexican TV presenter and Arsenal fan Patty Lopez. The world’s fastest man posted the forfeiture photos of him in a Gunners shirt on his Instagram account, complete with name and his world-record time of 9.58 at the back.
6. Plane and simple
Rugby being the big deal that it is in Australia and New Zealand, rival national airlines Qantas and Air New Zealand were understandably fired up for the 2015 Rugby World Cup final between the two nations. A Twitter bet was fixed thus: the crew of the losing side to don the winner’s kit - this after suggestions to repaint the loser’s fleet were rejected. The All Blacks defended their world crown with a 34-17 win, and the rest was history.
7. A diplomatic row
Politicians have never shied away from a bit of verbal sparring, but Australian sports minister Kate Lundy was forced to pay up after losing a bet with her British counterpart Hugh Robertson during the 2012 Olympic Games in London. Lundy backed the Australians to win more medals than the host nation, but ended up having to do a 1,000-metre row on Dorney Lake in a Team GB kit.
8. Boring, boring, board
Back to Australians and rugby, and the 2003 World Cup won by England. Former Wallabies winger David Campese ended up having to wear a sandwich board with the message “I admit, the best team won” and walk down Oxford Street in London, this after his prediction about England being a boring side. As England captain Martin Johnson lifted the trophy following a 20-17 victory over Australia in the final, Campese was getting ready to eat humble pie.