Vince Vaughn made a big impression on his female co-stars in new comedy The Dilemma with his unusual methods of acting.
Winona Ryder described the member of Hollywood's frat pack as a "volcano" while Jennifer Connelly revealed working with The Break-Up star was "wild" thanks to his improvisation on set.
Winona, 39, gushed: "He's like this volcano of creativity.
She went on: "It can be intimidating because he's so brilliant but he makes you feel so good about what you're doing.
"It was amazing, truly one of the most fun, exciting times I've had on a movie.
"I really learned a tremendous amount from him, I was very insecure about improvisation before and he's just the king of that. I really learned a lot."
Jennifer Connelly plays Vince's wife in the comedy, about a man who discovers his best friend's wife is having an affair.
The 40-year-old actress revealed: "It was wild. I've never worked with anyone who was quite like that.
"He's really great at [improvisation] so it's fun to see what comes out. He's really talented at that kind of thing."
The Dilemma, which was shot in Vince's home town of Chicago, is released in cinemas on January 21.