Reality hit “90 Day Fiancé” has grown into an entire industry for TLC, spawning countless spin-offs — and even spin-offs of those spin-offs. The series, which premiered in 2014, quickly resonated with audiences who were fascinated by the premise: Under the United States’ K-1 Visa process, in which an American’s fiancé from another country moves to the U.S. to get married, there’s a ticking clock. Couples have a short 90-day time window (hence the show’s title) in which they must get married — or their non-American citizen partner will have to exit the country.

There are now dozens and dozens of “90 Day” spinoff series, including “90 Day Fiancé: Happily Ever After?,” “90 Day Fiancé: What Now?,” “90 Day Fiancé: The Other Way” and “90 Day Fiancé: Before the 90 Days.” As a matter of fact, there are also spinoffs focused on individuals like “Darcey & Stacey” and “The Family Chantel,...