updated 10/02/2006 AT 8:25 AM ET
•originally published 10/01/2006 AT 2:40 PM ET
Isaac Hanson of the pop group Hanson married his longtime girlfriend, Nicole Dufresne, on Saturday in Oklahoma, PEOPLE has learned exclusively.
The groom, 25, and bride, 22, wed in a traditional ceremony at the Philbrook Museum of Art in Hanson’s hometown of Tulsa.
The music group Hanson, which includes brothers Taylor, 23, and Zac, 20, rose to fame during the summer of 1997, thanks to their hit single “MMMBop.” The trio returned in 2004 for a Carnegie Hall concert that was part of a three-month international acoustic tour to support the release of their CD Underneath.
As the oldest of the group, Isaac was the last to marry. Middle brother Taylor, who wed in 2002, welcomed a third child with his wife Natalie in September. The youngest of the group, Zac, married his longtime girlfriend, Kate Tucker, in June.
According to the band’s Web site, they are now are wrapping up their fourth studio album, set to bow early next year.