Hello , yes the word Swinger can be used for couples that have sexual relations with other people. like they switch their couples for fun... ( in my opinion I consider that is terribly awful ) if you saw that in a familiar tv show is likely a different thing. not the first option. but also it can be a different thing , the plural form of the word '' Swing'' which is common in the neighborhood parks ( kids parks ) is a thing that kids use for fun like little chairs attached with chains or ropes and it ''swings'' :) I hope it helps :)

Yes, that is the usual meaning to adults. To children, it would probably mean people that swing on a swing, which perhaps adds a little ambiguity. I have never seen the series, or even heard of it, so I can't comment on how appropriate a title like that is, but I did read a synopsis of that episode, and it is talking about sex education, so it sounds very appropriate.

That is correct. It refers a situation where groups of couples agree that the husband will have a sexual encounter with someone elses wife , and his wife will have a sexual encounter with someone elses husband. It was a term used in the '60's "free love" period. Think of it as wife and husband swapping. In the TV show I think it is used in a joking way, instead of literally, because the main characters in that show are NOT the type of people who would do that kind of thing.