Rob Reiner had an interesting career in films and television - as a director, and an actor.
Usually a person in "the business" is one or the other; Rob Reiner's body of work was kind of unique, in that way.
Before he directed any movies, he played roles as an actor in several TV-series on a one-time basis, and then in the hit show All In The Family, as one of the regular characters, seen there every week.
We can experience his acting on there by watching a You Tube video titled
The Bunkers and The Swingers
uploader / channel: All In The Family
Rue McClanahan appears in this episode - if you have watched "The Golden Girls" (in the '80s) you will remember her as Blanche Devereaux.
Isabel Sanford is in it, too. She is the one who finally has to tell Edith, "Those people are here to change partners, but - not for dancing. ..."