Mark Wahlberg shares photo of 20-pound weight gain for next role

"And it looks just as hot in person baby," Rhea Wahlberg, Mark's wife, commented with a heart emoji. Mario Lopez added: "Yo. You wear mad chubby well homie!"

Back with Kimmel, Wahlberg described the plot: "I'm playing a guy who was a fighter. He was many things. He was a fighter. He moved to L.A. to become an actor. He fell in love with a girl. He kind of had an accident. He had an out-of-body spiritual experience. He decided to become a priest. He died of a rare disease [inclusion body myositis], but he had a big impact on a lot of people in a very short amount of time. So, it's quite the story."

It has since been revealed that the film is titled Stu—directed and written by Rosalind Ross—and also stars Mel Gibson, Jacki Weaver and Teresa Ruiz.

In the meantime, Wahlberg's HBO Max documentary, Wahl Street, is streaming now.