If you meant a different series, here are the most likely candidates:
Watch Stewie's therapist share a pivotal story from his past during the Family Guy episode of the same number: [S16E12] Family Friend
Focuses on a tense family dinner hosted by Richard and Catherine to discuss their separation. Meanwhile, Levi Schmitt visits an ailing uncle and discovers a long-held family secret about his uncle's sexuality. If you meant a different series, here are
The detectives investigate the murder of Philip Cerullo, a retired police officer who was well-liked and had no known mob ties. A unique, limited-commercial episode featuring Stewie in a
A unique, limited-commercial episode featuring Stewie in a therapy session with Dr. Cecil Pritchfield (voiced by Sir Ian McKellen ). Stewie reveals secrets, including his "real" voice, and ultimately makes a dark decision regarding his therapist’s health.