James Franco is dishing on his romantic history.
The 38-year-old actor plays Laird Mayhew in his new film, Why Him?, an eccentric Silicon Valley billionaire who's trying to win over his girlfriend's father. ET spoke with him at the film's Los Angeles premiere on Saturday, when he revealed that similar to his character, he hasn't always been a hit with the ladies' parents.
"No fathers have disliked me like Brian's character dislikes me in this movie [but] there's been a mother or two that just didn't like me," James tells ET's Katie Krause. "I remember being very young and throwing pebbles at somebody's window and the mother coming out and treating me like a bum -- 'Get out of here, you scum!'"
WATCH: EXCLUSIVE -- Kaley Cuoco Gushes Over 'Perfect' Boyfriend Karl Cook at 'Why Him?' Premiere
These days, James says he's not as big on sweeping romantic gestures as he was in his teenage years.
"I've been pretty bad in the romance department," he admits. "I think I'm a caring guy, but the grand gestures I'm not great at. I need to put more work into it."
James also briefly dished on younger brother Dave Franco's upcoming wedding to actress Alison Brie. James says the 22 Jump Street actor is far from stressed about his big day.
"He's supposed to get married in February," James shares. "I think he's so casual about it."
ET spoke to Dave while he was promoting Now You See Me 2 in June, when he was indeed super relaxed about his upcoming nuptials. "We're pretty lax about the whole thing," he said of him and the former Community actress. "It'll happen when it happens."
Dave also said that neither James nor their brother, Tom, will be the best man.
"I don't know if I'm gonna have a best man," he mused. "I feel like when we do eventually get married, we're not gonna do a lot of the traditions and we're just gonna make it easy and who knows?"
Why Him? hits theaters on Dec. 23.
WATCH: EXCLUSIVE -- Bryan Cranston Says Working With James Franco on 'Why Him?' Was the 'Most Fun' He's Had on a Movie
ET was on the set of the hilarious comedy, when Bryan Cranston told us working with James was the "most fun" he's ever had shooting a movie.
"If you are actually cracking up on set and that's your job, it's amazing," James echoed. "But I never want to lose a great line or a great reading, so I really try not to laugh."