Yes, one of the irritating things about Hollywood is their constant insistence that if you are gay, you will eventually be murdered by rednecks. But actually, they glossed that over. It was a very short scene. The emphasis, or the tragedy of the story seemed more about Jack's frustrated desire to get Ennis to come and be with him. When he couldn't, Jack did start occasionally hooking up with other men. Interestingly, neither of them considered being with women to be "cheating," but near the end when Jack hints that he has gone down into Mexico on forays, and Ennis knows that to mean "other men," he is enraged.
What was affecting wasn't so much the two-lovers-kept-apart angle. It was more the difference between the two of them. Jack really wanted Ennis around all the time. Ennis was able to focus on his regular life when they weren't together. He was very matter-of-fact about things.
After Jack is dead, Ennis goes to Jack's parents hoping to take Jack's ashes and scatter them on Brokeback, but the father refuses to hand them over. He tells Ennis that Jack had been hooking up with some other man that last year, and it's kind of interesting that they portrayed Jack as rather weak and plaintive. Ennis is much stronger, or more stubborn.
Just curious why you went to see Brokeback...I wouldn't want to help it make money. Aside from the gay aspect, I've been avoiding R-rated movies in general.
Did you see Walk the Line and Cinderella Man?