Crowds of Westlife fans descended on a small register office in Wicklow town this afternoon to catch a glimpse of band member Nicky Byrne as he married the Taoiseach Mr Ahern's daughter Georgina.
A large-scale ceremony is planned for France on Saturday but today's low key event was needed because French law requires marrying couples to be living in the country for 40 days for a marriage to be legally binding.
Byrne wore a red baseball cap, T-shirt and jeans for the casual event at Wicklow Registry Office at 3.30pm. He was met by about 100 young fans who had gathered outside from early in the morning.
But there was no kissing or posing for the cameras as the pair left separately - meaning that their 1m deal with Hellomagazine will remain exclusive.
Westlife fan Nicola Dargan (13) saw the pair as they left the registry office. She said: "Nicky looked happy. He was wearing a red cap and he looked lovely."
Another onlooker, 13-year-old Ruth Neiland, added: "He looked gorgeous. But he looked very casual, it was as though it wasn't his wedding.
"He just walked right in and didn't say anything but he still looked lovely."
Hundreds of guests will head to France for the pair's wedding in the luxury Chateau d'Esclimont on Saturday.