Ryan Tubridy and Aoibhinn Ni Shuilleabhain have called time on their relationship after four years together.
The couple, who always remained tight-lipped about their romance and rarely appeared in public together, announced it was over via a statement from their agent.
And while the news broke, Tubridy took to our screens for the last Late Late Show of the year, welcoming some of the most stellar guests he's had on the show this season including Take That, actor Aidan Gillen and singing sensation Hozier.
Agent Noel Kelly released a statement on behalf of the former couple last night.
"Aoibhinn and Ryan are no longer together," it read. "They will remain friends and ask for privacy at this time. There will be no further comment on this personal matter."
The pair started dating in 2009 after he interviewed the former Rose of Tralee for his Saturday night chat show. The loved-up couple were first snapped together strolling hand in hand in Powerscourt Gardens.
Aoibhinn (30) previously revealed that she fancied the RTE star straight away after appearing on Tubridy Tonight five years ago.
"Of course I fancied him. I hadn't thought about it before then, but we had great fun on the show and afterwards," she said. "Ryan is one of the funniest people in the world and constantly has me laughing. I definitely look to him for advice.
"It's nice when two partners work in the same industry, because when you get home, the other person understands what you are talking about.
"We can bounce off each other, as we both know the personalities and games out there."
Tubridy recently revealed that he had to have a few drinks for Dutch courage on the night he asked Aoibhinn out, and opened up about how he found her "very pretty, beyond smart and extraordinarily intelligent".
The pair were rumoured to have split briefly last year but they never confirmed the separation. The couple had moved into a €1.25m house in the South Dublin area of Monkstown last year and Aoibhinn recently insisted that they were happy living together but had no wedding plans.
"Ryan and I are living together and are very happy," she told the Herald recently. "We have no plans. We're happy just doing what we are doing."
A source close to the couple believe they will stay friends despite the split. "They have been together for years and they are so similar intellectually that there will always be a friendship there."
Late Late Show host Ryan (41), has two daughters from his previous marriage to RTE producer Ann Marie Power.
Despite the split, it's been a great week for Aoibhinn as she graduated from Trinity College with her PhD.
The newly-single brunette was delighted with her achievement, tweeting: "You can call me Dr - just passed my PhD viva".