"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

Costar Glenn Howerton, who lived with McElhenney, said Olson would suddenly be too drunk and need to stay over.

For Kaitlin Olson and Rob McElhenney, looking back on their whirlwind romance will always be a sunny time. The couple first met when Olson auditioned for the role of Sweet Dee for McElhenney’s show, It’s Always Sunny in Philadelphia.