Levine was spotted at The Mercer Kitchen around 2 p.m., an onlooker tells PEOPLE.
"He looked really laid back and seemed to be in a great mood," the source adds. "He was laughing a lot and was really enthralled in the conversation the whole table was having."
Joined by a group of guys and one girl – who was wearing a very big hat – Levine, 33, kept things casual in a gray hoodie and jeans.
– Jennifer Cress