Walking in on his brothers "Private time"

Arnold lived at home. He shared a large house with his parents, his sister and his brother. They were not twins but both of them look quite alike; People getting them mixed up when together wasn't uncommon despite his brother being a few years older then him. His name was Carter and Arnold didn't get on with him well. Carter wasn't exactly a bully but at any change to tease his little brother he would take it.

Arnold had felt hungry, he looked to his clock as he got out of bed. It ready 2am. He yawned, gave a little stretch and nearly walked out of his room. Luckily he had looked in his mirror and stopped himself. Looking back at him was a naked guy, little dick fully out. He blushed and quickly raced back and threw on a gown. He was glad to have noticed that, he would have hated to have been seen naked. As he stepped out of his room he could hear the sound of his brothers TV though the walls. Carter never paid much attention to his tv and would often leave it on, wasting electric and running up the bills. Arnold sighed and decided to head in and switch the damn thing off! What greeted him as he opened the door however shocked him.

As he entered Carter was at his desk that faced the door, pants around his ankles, dick in hand, pumping away!
"What the fuck?!" he hissed out as he saw Arnold staring at him. He quickly tried to stuff his dick back in his pants. This was when Arnold learnt a sad, sad truth about his brother. The two were similar in many ways, but Carter actually had a decent sized dick. At a glance it looked to be at least 6 inches long!
"BRO WHY THE FUCK ARE YOU NOT GOING!" Carter screamed. Arnold blushed and panicked.
"L-look I don't know! W-why the hell are you so hung?!" he burst out. His brothered wicked smiled made him realise he just made a mistake.
"Oh? Are you not? Gonna compare?" Carter joked. That was all too much for Arnold who quickly shut the door and ran back to his room, not even getting food.