An early scene in It’s Always Sunny in Philadelphia season 17, episode 6 features Rob Mac and Kaitlin Olson’s sons Axel and Leo McElhenney, though it isn’t their first appearance on the hit sitcom. Cameos by family members of It’s Always Sunny in Philadelphia ’s main cast have long been a series tradition, but while most appearances have included the actors’ spouses, recent seasons have begun integrating their kids.

Among the most memorable familial castings have been Danny DeVito’s wife Rhea Perlman , Charlie Day’s wife Mary Elizabeth Ellis (who has starred as The Waitress since season 1), and Glenn Howerton’s wife Jill Latiano. More subtly, Rob Mac has also included his and Kaitlin Olson’s sons, Axel and Leo McElhenney, in unnamed roles, which he does again in It's Always

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