Leighton Meester goes without makeup in first selfie since her secret wedding to Adam Brody. Credit: courtesy of Leighton Meester

Gasp, what would Blair Waldorf think? Gossip Girl star Leighton Meester had no problem going without makeup in her first Instagram selfie since her secret wedding to The O.C.'s Adam Brody was exclusively revealed by Us Weekly last week.

The actress, 27, best known for playing chic Upper East Side Queen Blair Waldorf on the hit CW show, was dressed down in a flannel shirt and a beanie, holding up a copy of John Steinbeck's Grapes of Wrath without flashing her left hand. 

"Celebrating John Steinbeck's birthday today w/my @miceandmenbway family," she captioned the photo. 

Meester is starring in the Broadway adaptation of Steinbeck's Of Mice and Men with A-Lister James Franco and Bridesmaids star Chris O'Dowd. The show goes into previews on March 19 and opens on April 16 for a limited engagement through July 27. The actress will play Curly's wife. 

Meester has yet to comment on her marriage, but her hubby gave a quicky monosyllabic confirmation to photographers on Feb. 18.