Costar Glenn Howerton, who lived with McElhenney, said Olson would suddenly be too drunk and need to stay over.Actor Glenn Howerton didn't even pretend to be happy when he found out that roommate Rob McElhenney was dating Kaitlin Olson,

It's Always Sunny in Philadelphia' costars Rob McElhenney and Kaitlin Olson, who are married in real life, say his neurodivergent diagnosis was positive for them.

"The stupidest thing you could possibly do is to date your co-star," Howerton said while recalling the start of McElhenney and Olson's romantic relationship