The actor was spotted wearing blue jeans, a light gray t-shirt and blazer, arriving solo at Barton G. The Restaurant in Los Angeles. His children -- Violet, Seraphina and Samuel, whom he shares with ex-wife Jennifer Garner -- arrived later bearing gifts.
Earlier in the day, Garner was also seen at the Brentwood Country Mart carrying a white package -- perhaps a birthday cake? The 45-year-old actress was ravishing in light blue jeans, a white blouse and tan heels.
Affleck arrived to his birthday dinner at Barton G restaurant a little before 6 p.m, a source tells ET. The actor's three kids arrived after him with a nanny, though there was no sighting of Garner at the restaurant. Ben left around 8 p.m. carrying a brown box and seemed to be in a good mood, leaving in the black limousine he arrived in.
An eyewitness told ET that, while at the iconic improv and sketch club, "Ben was hugging Lindsay from the back as they turned in their tickets," and both appeared to be in a "good mood," and were "enjoying a casual date night."
For more on their date night, watch the video below.