Speaking on the Late Late Show last night, the athlete explained: "I asked Aoife out and she said no."
The pair met at a photo shoot but the former Miss Ireland was going out with someone at the time. A few years later Aoife split from her then-boyfriend and, when D'Arcy heard she was single, "absolutely had to" ask her out again.
He said he had to work up the courage to ask someone out for the second time, but was urged to by a mutual friend.
The couple appeared on the show to promote their new joint business venture - Reformer Pilates.
Explaining their reasons for going into business, D'Arcy said: "rugby is a career that will go for a very short amount of time. It's also a collision sport."
"Every game could be your last," he added.
While the rugby player manages the financial side of things, he says his wife is 100% the boss - "she's running the show".