
I JUST WANT TO KNOW WHY THE GUY FROM THE BAR GETS ANGRY TO WATANABE?

It's a bit late, but just in case somebody else is wondering: the guy from the bar isn't mad because he finds out what Watanabe was doing. He already knew what Watanabe was doing to Hazuki, he even warns him to not get hurt; he got mad because Watanabe said that he couldn't get serious with a man, fully knowing that he's in a gay bar.
I WOULD HAVE THE SAME REACTION WITH NAKYUM IF I WERE IN HIS PLACE