Jessica Chastain's grandmother has developed a crush on the actress' movie dad Matthew Mcconaughey.

The Help star's gran has become a regular at the Oscar winner's red carpet events and premieres, where she gets to meet her movie idols - and she was bowled over by charming MCConaughey at a recent Interstellar screening.

He now has taken over from Al Pacino as grandma's leading man.

The actress explains, "My first job was working with Al Pacino and my grandmother took a picture with him... and she framed it and put it on a bedside table... I thought that was the biggest goal of her life, you know, that picture of Al Pacino. There is one man who has surpassed Al Pacino in my grandmother's eyes, and that's Matthew MCConaughey.

"He flirted with her like I've never seen. They met at a screening of Interstellar and my grandmother was so starstruck: 'I want a selfie, Matthew!' She then proceeded to do a photoshoot in front of everyone. Like, 'You stand there', and she just started taking pictures of Matthew."