Why are they talking about [ketsu] during a cool scene?

Reze says "ass" means [ketsu]

It seems overseas asshole... [ketsu no ana] is used as slang to mean an unpleasant person

Hmmm

You damn bastard!!

In the middle of watching a movie

~A few years later~

I'll even tongue your butthole for a week to thank you!!

*In other words... You damn bastard!!!

No tonguing necessary.

Not while you're under our protection anyway.

*In other words... If you escape you'll have to lick my asshole

Yoshida doesn't know the meaning of this slang...!!