Olivia Wilde & Jason Sudeikis Look 'So in Love' in Venice
03/15/2013 AT 06:00 AM EDT
Olivia Wilde and fiancé Jason Sudeikis stepped out for dinner with a group of 12 friends on Wednesday night at Axe, a restaurant in Venice, Calif.
Sporting a tan skirt and white and navy striped top, Wilde looked "stunning with almost no makeup," an onlooker tells PEOPLE, while Sudeikis wore a denim jacket over a button-down shirt.
Sitting side by side in the middle of a long table, both were in very "energetic and happy moods" as they made the rounds to greet their friends.
The table dined on dishes including flat breads with hummus and farmer's market vegetables.
The Incredible Burt Wonderstone actress and Saturday Night Live star sipped on rosé and "looked so in love, it was hard not to smile just watching them," the source says.
"They were very sweet and affectionate and seemed completely head over heels for each other," the source adds.
– Jennifer Garcia