There are plenty of reasons not to date your costar on a movie or TV show — not that that’s stopped plenty of Hollywood stars from doing so — but Matthew McConaughey has a simple one: It’s not good for the onscreen product.

In an interview on The Howard Stern Show to promote his new memoir, the Magic Mike star explained that movies starring couples “on the approach” are better than movies starring married couples. “If you look at the history of films, when you see a couple, say they did a movie together and then later on they get married, and they make another movie together,” McConaughey said. “Once they get married, you watch that movie, they’re not near as good together. It’s the movie when they met that you go, ‘That’s the one [where] this thing is sizzlin’.'”

On a more serious note, McConaughey added that he preferred to “keep it professional” when working with actresses like Kate Hudson and Sandra Bullock. “Maybe we had certain crushes on each other at certain times, but we always just kind of kept it professional,” he said. “Or maybe we were dating somebody seriously at the time, and we both respected that.”

However, McConaughey did in fact date Bullock for a time after working with the actress on 1996’s A Time to Kill, and also dated Penélope Cruz after they met on the set of 2005’s Sahara, though it’s unclear when exactly those relationships began.

Asked if it’s difficult to stay a married man in Hollywood (McConaughey has been married to model Camila Alves since 2012), the actor noted, “I personalize Hollywood in my book. I write about her: ‘I want her, I don’t need her.’ She’s a moonlight tryst….A certain amount of fame is for rent, and my wife and my family, in my mind, are non-negotiable. And so the non-negotiable things in my life, when I’ve watered their proverbial garden, that’s when my garden grew and I flourished and I became more me and life felt more vitale.”