Wait, it feels good?

This is my first story on here, so please leave all the criticism you want, I can take it.

Dylan walked into his room, locking the door behind him. He knew what he needed after a hard day at school. As usual he turned the TV on, and walked to his chair, where he pulled his laptop over to his lap, whipped out his semi-large dick, and began to stroke lightly as he opened up a video of an eighteen year old girl, who grabbed a light pink colored vibrator, which she used to pleasure herself while making slight moans and groans.
*Knock Knock Knock* “Hey Dylan! You in there?”
“Uh, Yeah hold on!” Dylan said frantically as he pulled up his pants and closed the laptop. He knew that if he didn’t Jessica would instantly tell their mom what he had been doing.
“What is it?” He said as he unlocked and opened the door, to his little sister. He couldn’t help but notice that her small little nipples were bleeding through her tank top, with the green skull logo. Her dark black hair, was falling just past her solders and she was wearing a frilly pink miniskirt. Her legs were long and slender, and her breasts were small. Dylan didn’t pay much attention because she was his sister, he didn’t want to do anything to her.
“I need help with my math homework, I don’t understand inverse operations.” She said innocently.
“Well I’m watching TV right now, so could you-” He began
“No, I need help and whenever you get distracted, you end up forgetting to help me at all!” She whined stomping her foot on the ground causing her pink miniskirt to show just a slight gimps of her rainbow colored panties.
“Fine.” He said “Go to the kitchen, I’ll be out as soon as the next commercial.”
“You better be!” She said angrily, as she stormed out of the room down the hall.
Dylan quickly closed the door and jogged over to his laptop opening it and starting up his porn video once more. He skipped the slow stuff, If he wanted to finish he was going to have to be vigorous. He watched as the young blond woman began to groan loudly into his headphones. He yanked his now very stiff member and finally reached the point of climax when-.
“Dylan how long is-” Dylan froze, and looked to his door, Jessica was standing in the doorway with a face that said “Oh, your in for it now!”
“Get out!” Dylan screamed, covering his raging hard on with the laptop. “How did you unlock my door anyway!” He shouted to his sister.
“It wasn’t locked!” She said still staring at his boner. She was right, in all the rush, He had forgotten to lock the door, how could he be so stupid! He thought to himself.
“Stop staring and leave!” He said sternly, trying to hide his softening cock.
“Fine fine, but you better get out there and help me with math” She said and casually walked out.
“MATH!” He thought “How can she care about math at a time like this, she just saw my complete and total boner!” Regardless he put on his pants, positioned his halfey so that it wasn’t as noticeable.