LeAnn Rimes and Eddie Cibrian
04/10/2012 at 06:00 AM EDT
and Eddie Cibrian
acted like one big happy family with the actor's boys in tow on Sunday, as the clan celebrated Easter at Venice, Calif., restaurant Gjelina.
Clad in a cream sundress and heels, Rimes "was very doting on Cibrian's two sons," an onlooker tells PEOPLE, adding that that she and her hubby
"were adorable with one another."
Cibrian – dressed in a blue and white gingham button-down shirt – and his family dined at the trendy eatery for nearly two hours, heading out the back door just before 1 p.m. – Jennifer Garcia