updated 08/17/2011 AT 5:00 PM ET
•originally published 08/17/2011 AT 2:55 PM ET
David Cross and his longtime girlfriend, Amber Tamblyn, are engaged to be married, her rep confirms to PEOPLE.
The actress, 28 – who starred in General Hospital and Joan of Arcadia before moving on to the big screen in the 2005 hit The Sisterhood of the Traveling Pants – recently returned to TV with a role on House.
Cross, 47, is perhaps best known for his outrageousness on the 2003-06 cult sitcom Arrested Development, on which he played the gaffe-prone, madcap Tobias Fünke. Talk of a feature movie based on the show has long been circulating. Currently, he stars in the British-American comedy TV series The Increasingly Poor Decisions of Todd Margaret.
Earlier this month, the couple were spotted on the patio at Oscar’s Cerveteca in Venice, Calif., where they met friends for drinks – beer for him, rosé for her – and casual conversation.