Mary dates a handsome ski instructor (Rob...

Mary dates a handsome ski instructor (Rob Wolders) but her friends don’t know what she sees in him on The Mary Tyler Moore Show (Sunday at 10 p.m. on Nickelodeon).

Lucy tells Ricky she’s pregnant on I Love Lucy (Monday at 1:35 a.m. on TBS).

Mark Harmon appears as Sam, Maddie’s old flame, who returns to woo her much to David’s chagrin on Moonlighting (Tuesday at 3 p.m. on Lifetime).

Barbara Barrie plays a junior high school principal with whom Murray considers having an affair on The Mary Tyler Moore Show (Tuesday at 10 p.m. on Nickelodeon).

Richard Haydn (“Ball of Fire,” “Sound of Music”) is a guest on The Dick Van Dyke Show (Wednesday at 10:30 p.m. on Nickelodeon) in an episode in which Rob rounds up three stars from the old days of radio for an Alan Brady special.

Stefanie Powers plays agent April Dancer and Noel Harrison is her partner Mark Slate on The Girl from U.N.C.L.E. (Thursday at 1:30 a.m. on TNT), the 1966-67 spinoff of “The Man From U.N.C.L.E.”

David and Maddie finally consummate their relationship to the strains of the Ronettes’ “Be My Baby” on Moonlighting (Thursday at 3 p.m. on Lifetime).

Mary Tyler Moore directed “A Boy’s Best Friend” episode of The Mary Tyler Moore Show (Thursday at 10 p.m. on Nickelodeon), which finds Ted’s mother deciding to live with her boyfriend instead of marrying him.

Lucy gives birth to baby Ricky on a historic episode of I Love Lucy (Saturday at 1:35 a.m. on TBS).

Paul Sorvino (“GoodFellas”) appears as David’s divorced father on Moonlighting (Saturday at 11 a.m. on Lifetime).

Every Saturday this month, Nick at Nite presents Very Very Emmy Month (Saturday at 10 p.m. on Nickelodeon), which features four back-to-back episodes of series that have won Emmy Awards for their writers, directors and performers.