It’s important that readers know they can leave this post at any time. Last night, James Corden welcomed Jamie Dornan to his own “Fifty Shades” dungeon — this one is way, way creepier than what Dakota Johnson has become accustomed to.

You see, the “Late Late Show” host’s “playroom” is full of train sets. Like, a lot of train sets.

“Say something, please,” Corden implores his speechless guest — straight out of the best-selling novel and film trilogy scripts.

“You’re a nerd,” the man behind the big screen’s Christian Grey character finally blurts out.

Also Read: 'Fifty Shades Freed' Film Review: Trilogy's Tame Finale Lays Us Down to Sleep

After some apprehension on Dornan’s part, the two fellas really get into playing conductor. The innuendo only increases from there — just wait until “Signal Master” Corden and his Tuesday guest blow their steam train’s horn.

Watch the video above. Somehow, it’s still pretty sexy. (Answer: It’s the music — and, we suppose, Dornan.)

“Fifty Shades Freed” chug-a-chug-a-chugs into theaters on Friday.