He was sent to fight in the Battle of Normandy but later wrote to her from the United States, saying she should join him and "make my house a home". But she misunderstood the invitation, thinking he was already married and intended to leave his wife for her.
She refused his offer and the two went their separate ways. Both married and had children. She moved with her husband to Adelaide in Australia and was divorced after 30 years; his wife died more than a decade ago.
Last year, Mrs Morris asked her son to try to find him on the internet and the couple were able to talk on Skype after discovering a story about Mr Thomas going skydiving on his 88th birthday. An online crowdfunding campaign raised enough money for him to fly out to see her and Air New Zealand offered free first-class flights for Mr Thomas, 93, and Steve, his son and carer.
When the couple were finally reunited, he fell into her arms and they hugged. Mrs Morris was just 18 when they last saw each other.
"We'll have a wonderful fortnight," she said. "To find somebody who loves you and you love them, in the latter years of your life, it would rather be special, wouldn't it?"
The couple plan to spend Valentine's Day together.
Mr Thomas said: "This is about the most wonderful thing that could have happened to me."
During their Skype chat, he'd said: "I tell you what. If you had come to the States when I asked, we would have been together for 70 years."
He remembered the teenager as a "pretty little thing" and told the Virginian-Pilot before flying out of the US: "Joyce was special; the one that got away. But after the war, my orders to go home came so quick there was no real chance to even say goodbye."
He added: "I'd rather die travelling to Australia than live sitting around at home wondering 'what if?'."
