Folks who aren’t the biggest fans of Adam Sandler’s brand of humor might find it hard to believe, but he’s never starred in an R-rated comedy — until his latest, “That’s My Boy,” that is. While his rare dramatic efforts generally get the restricted rating, Sandler has stuck firmly in PG-13 territory when it comes to his comedies. And it’s paid off for him: In the past five years, only two films starring Sandler — the drama “Funny People” and last year’s dismal “Jack and Jill” — have grossed less than $100 million at the U.S. box office. So if playing to the middle school crowd had proved so lucrative for him, why risk ramping up the raunch now?

“I’ve done some stuff in the past few years where I’ve cursed a bit and it felt good,” Sandler admits, though he says his decision to go with the R-rated “That’s My Boy” was purely motivated by the story itself. “It was just a funny script. … [Andy] Samberg actually called me up and told me that he liked it, and that got me excited. That’s it.”

But certainly, for Sandler, that’s not really it. After all, in the past few years R-rated comedies have become a viable proposition for studios once again, especially with the success of films like “The Hangover” and “Bridesmaids.” For a man that’s made millions keeping it clean, such a sea change couldn’t have gone unnoticed.

“It was fun to speak the way that I speak in my bathroom,” Sandler says. “I grew up cursing a lot. … My parents told me to stop. They weren’t enjoying my albums, and they weren’t enjoying a lot of the things I did with my life. And then my father passed away, and he’s not here to yell at me anymore. I bullied my mother and said, ‘Here comes some more dirtiness. Sit and enjoy it.'”

Still, as much fun as Sandler had, he insists he’s still taking everything on a project-by-project basis — though that of course could change if “That’s My Boy” performs well. “If a movie comes to me that is rated R and I like it and connect with it, I would do that,” he says. “I don’t know what I’m doing next. I never know what’s coming next. I definitely yell at people in my life going, ‘What the f– am I doing next?’ a lot.”

SNL memories

Co-starring with Andy Samberg — who recently announced his departure from “Saturday Night Live” — gave “SNL” alum Adam Sandler a chance to think about his own departure from the long-running comedy show 17 years ago. “You’re scared when you go. ‘SNL’ is a home,” Sandler says. “When that goes away, there’s no life jacket. You’re just on your own and you’ve gotta figure it out.”

As for what advice he has for Samberg, Sandler warns that the hardest part will come this fall when ‘SNL’ returns without him. “I remember watching the show after I left and I was like, ‘Oh s–, they can do it without me! That hurts,'” he says.