S1·E16 Jeff's Double Life
Aired January 7, 1959
Synopsis
After nosy neighbor Mrs. Wilgus (the inimitable Kathleen Freeman) alerts Donna and Alex about Mary having a noisy party while they were out, the kids get lectured about being the children of a doctor, and that they should behave accordingly.
Not too long after this, Jeff takes a ride from Mary's troublemaker friend Tommy Hendricks, who doesn't have a license and has taken his father's car out for a joyride, and they get into a minor accident while fleeing a cop.