"We raised a few eyebrows but we got on like a house on fire," he said.
They married when she was 18 and in 1965 moved to Hawke's Bay for his job as a policeman, where he was active in liquor licensing and was a prosecuting sergeant before retiring in 1987.
They raised five children and have 10 grandchildren.
Bicycles and the law also featured in Anne and William O'Sullivan's relationship. The pair worked in a Dublin bakery and spent their courtship tramping and cycling.
One day a policeman stopped them after spotting William riding alongside Anne with his hand on her shoulder, and he was charged with holding on to a moving vehicle.
In court he was defended by his father, a legal advocate, who had the case dismissed on a technicality after strenuously complaining to the judge about the description of his future daughter-in-law as a moving vehicle.
After their wedding they emigrated to New Zealand where he left the baking trade to become a tanner at E Astley & Son in Auckland, later bought by Hawke's Bay's Lowe Corporation.
They raised four children and have 11 grandchildren and three great-grandchildren.
They moved to Hawke's Bay 15 years ago, following their daughter Mary Horner and her husband Ian.
Yesterday both couples received a special diamond anniversary blessing during a service at Our Lady of Lourdes church in Havelock North.
They will spend the weekend celebrating with their extended families.
Mr O'Sullivan said the secret to a happy marriage was give and take.
Mrs O'Sullivan said talking was key.
"If you have a disagreement talk it over before you go to bed," she said.
Mrs McCormack shared a similar sentiment.
"Sulking is the worst thing you can do," she said.
Mr McCormack said he was an easy man to please.
"Never disagree with your wife."