Alan Robinson and Walter Macfarlane spent the last 60 years as best friends, not knowing that they're actually brothers

For the last 60 years, Alan Robinson and Walter Macfarlane have been best friends. But their relationship took a turn recently when they learned that they’re much, much more than that.

In fact, Robinson and Macfarlane are brothers.

Both men were born in Hawaii just 15 months apart, and first met in the sixth grade at a prep school in Honolulu, the Associated Press reports. While Robinson had been adopted, Macfarlane never knew his father. So, the pair separately set off to find out where they came from.

“I thought, ‘I’ll never know my birth mother, I’ll never have any nieces or nephews,’ ” Robinson lamented to KHON.

Macfarlane turned to DNA matching websites in his search, and was matched with a user called “Robi737.”

“As a nickname, everybody called him Robi and he flew 737s for Aloha Airlines, he was a pilot,” Macfarlane’s daughter, Cindy, told the station of Robinson.

Best Friends Brothers
Credit: KHON/AP

After a few phone calls, the men learned that they have the same birth mother. Macfarlane said the news came as a “shock,” but the men admitted they had their suspicions that they might be related.

“When you thought about it, compared forearms and everything,” Macfarlane said, according to WHDH. Robinson added: “Hairy arms! That did it!”

The pair broke the news to family and friends during a party over the weekend, the AP reports.

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“It was an overwhelming experience, it’s still overwhelming,” Robinson told KHON. “I don’t know how long it’s going to take for me to get over this feeling.”

He added: “This is the best Christmas present I could ever imagine having.”

The brothers said they plan to travel and enjoy retirement together, according to the AP.