I recently watched an episode of “Cheyenne” from 1957 that had James Garner as the villain, and Angie Dickinson as the damsel in distress. Unless I missed an episode, it’s also the episode showing the closest Cheyenne ever came to committing adultery. And her husband was right there! (but comatose).
This is almost exactly what I was going to post. Jerry and George dated a lot of different women over the course of the series, and a number of actresses who went on to star in other shows appeared as one or two episode love interests or other characters. (Mariska Hargitay played an actress who was auditioning for the role of Elaine in “Jerry”.)
Appearances in minor roles on these shows is often a major factor in the career development of actors. It gives directors and producers an opportunity to see the actors working in actual production, and to find out the work ethic of the actors. Auditions are like first dates, and not necessarily indicative of how a relationship would work out.