Despite currently going through a very public separation from his wife Paula Patton, Robin Thicke put his best face forward on Monday night in West Hollywood, to celebrate his 37th birthday with a crew of pals and a slew of alcohol.
Among the males in Thicke's exclusive guys-only group? Leonardo DiCaprio, who arrived with the "Blurred Lines" singer at DBA night club, where the birthday boy seemed to be "in a great mood, enjoying time with his friends," a source tells PEOPLE.
Thicke and his entourage sipped on tequila pineapples and Amstel Lights, the source says. They toasted to the momentous occasion with some Cristal champagne, and continued with what seemed to be the males-only motto of the night, as the insider explains: "No girls were allowed in their booth."