Chaz Bono Mama's Boy

Cher hung out with her new son last night -- 40-year-old Chaz Bono.


The singer, Chaz and his GF Jennifer Elia all met up at an L.A. art studio for an event for Cher's other son Elijah Blue.

As we previously reported, Chaz began gender transition last year ... with his mother's full support.