In an interview with GQ Australia the Suicide Squad star talks about being raised by Dirty Harry himself and the time he was slammed against a wall and punched in the face by his father when he was 16.

The 30-year-old recounts the time when he was 16 and took his younger sister, Kathryn, to a party where he abandoned her in order to enjoy a beer with his mates. She was 14 at the time.

"Later, dad found out... He popped me in the face and said, 'You don't ever leave your sister at a party. EVER.' And it was very old-school, very old-school of him. He was not afraid. None of this new-age bullshit where you can't even smack the kid because everyone's so afraid of being judged or whatever. That wasn't the way shit went down in that family… If you did something wrong, you were gonna get punished. I learnt quickly - you don't do that," he said.

Despite the growing up in a strict, 1950s-esque household, where the "Code of Eastwood" was to be maintained at all times, he has a close relationship with his 86-year-old dad. Not once in the lengthy feature, which was reportedly written after the writer, Adam Baidawi, spent 20 hours with him, did Eastwood "belittle, devalue, or question his old man".

Eastwood has only recently taken his father's surname, preferring instead to go by his mother's maiden name when attempting to crack into the film industry.

He put himself through school and was a bartender before landing roles – a cameo in Gran Torino (where Eastwood snr calls him "a pussy") and as Taylor Swift love interest in her Wildest Dreams film clip.

While he was studying and juggling work his dad declined his request for a $8000 loan to buy a car. Even after Scott had laid out a repayment plan.

"I remember the phone going silent… And he'd just be like, 'Yeah, no.  You're fine with what you're doing.' He wouldn't give me a dime," he said.

Proving the apple doesn't fall far from the tree, when asked about his pet peeves "complainers" is on the top of his list.

"Whiny little f---ing brats. You just really want to knock them out and be like, 'You lucky, lucky, spoilt brat. You're full of yourself. You're so lucky, I would love nothing more than to knock you out, to show you how much of a little brat you're being," he said.

The wide-ranging interview also describes how the death of a girlfriend in a car accident several years ago "made it harder for me to date".