...

I think so too.

Well, I hope YES, because the only other option that comes to my mind if it's not him (the twin) would be Woo-Jin... Now, THAT would be awful...

I think so too (⊙…⊙ )

They said his name in the film and it wasn't his brothers name it was some other guy

Ok I want to just know, clarify and learn some things. Firstly yes they are twins but doesnt the younger brother call Yoon tae Min "hyung" (or something's like that) can't he call him something else I think it begins with a c can't remember which mean they were born of the same year? I think the word was "chingu" I can't remember tho...

the names is a problem for me（￣へ￣）that's why normally i reread them all and I make some schematics too... (￣∇￣")

I considered that, too, but I think it should be impossible. In the beginning, Woo-Jin is irritated by the impression he (Tae Min)'s being slutty, like some people say about him.
If he were that director, there would be no reason for him to wonder whether Tae Min gave his ass to other guys or not, he would just know it for sure.

Then, I must be honest, I don't like Woo-Jin but… that is not his character. His aggressiveness expresses itself trough detachment, not brutality. It's been said that his violent reaction against Tae Min is a unique, right?

About the name they use in the movie to address the director: considering the nature of it, they might be using a nick, to avoid future problems.

That bastard. I really dislike him, but I still hope it's not him. To let (or even provoke someone) to rape your own brother it's too much.