So it kind of goes without saying that David Corenswet, Rachel Brosnahan, and Nicholas Hoult will be back after the events of Superman, in theaters July 11. But if you ask them about it, they aren’t so sure.

Superheroes have not been complete strangers to R-rated movies. All three "Deadpool" entries were R-rated as was 2017's "Logan". But traditionally the studios have made sure to restrict R-rated material to darker characters like Wolverine and Deadpool.

In fact, the idea of Lex Luthor and the Joker teaming up is the subject of the classic animated movie The Batman/Superman Movie: World's Finest, which marks the first crossover between Superman: The Animated Series and Batman: The Animated Series all the way back in 1997.