The actor, 38, strips for the part in the film Outlaw King.
He tells the Graham Norton Show: “I bare the ‘full monty’ and it got a lot of attention... What did strike me most is that (co-star) Florence Pugh bares everything too and no-one commented.
“I am not sure what that means. Either people think they can’t comment or everyone expects women to get naked. Either way, it’s double standards.”
Pine has previously said of the scene: “It was a man coming out of the water taking a bath, it seemed a little odd to wear underwear.”
The US star told host Norton how he continued to use the Scottish accent he learned for the role after filming each day.
“I figured I’d get crucified for it but I had a wonderful voice coach and the cast were all Scottish so I figured they would pick me up on things,” he said.
“I am not a method actor, but I would keep up the accent in the pub after filming.”
The new Netflix biopic depicts the story of how Robert the Bruce led 500 men to defeat the larger and better equipped English army.
The Graham Norton Show, also featuring Sir Michael Caine, actress Sally Field, US actor Rami Malek and Christine And The Queens, airs on BBC One on Friday at 10.35pm.