My cousin and I

This is another story about me and my cousin and how we used to have jerking sessions.

My cousin was a curious young teen, around 13 at the time, he was short and pretty skinny and was just beginning to hit puberty as I learnt in which I will elaborate soon.
I was 17 at the time with an average build and average body.

By this time we had already had some jerking sessions but this is the story.
Me and my cousin were pretty close and I would go over to his house on a regular occurrence, one afternoon I got invited by him to go over and play some computer games and watch the soccer, we both knew exactly why he invited me.

I arrived around 7pm where we played some ps3 and did the usual stuff teens do, around 10pm we had got sick of playing ps3 and we just chucked on some music and chilled, as this happened my cousin had got up and started dancing to the music and begun to strip, it was giving me a decent semi hard on. My cousin had also a semi hard on whilst dancing which was making me horny. My cousin wasn't shy of showing himself off which was cool.

After he had put his clothes back on we were chilling on the bed when I was on my phone going through photos of naked girls on my phone, showing them to him to try and get him horny and give him a hint for our mutual jerk off session.
I told him I was 'going to bed' which he also obliged.

I pretended to go to sleep and faced the other way to see how he would react, what happened next was a first, my cock raging on a hard he reached over and begun to stroke it through my boxers a little, my cock had never been touched by anyone else and I almost came right there and then.
After a while he stopped and I turned around and we decided to chuck on some porn on my phone.

He was loving it and I could tell he was on a huge hard, I tried to reach over and return the favor but he was a little nervous and kept pushing me away.
As we rolled over to begin jerking I could see the outline of his cock in his silk boxers which got me hard, he began pulling them down but held the bed sheet over his cock, the sheets tented up and he began to make some jerking actions so I joined.

I was getting so horny and was close to exploding but I held it back, I pulled the bed sheets off and there he was, a solid 5 1/2 inch uncut cock, he was jerking it fast and it was getting bigger. We were both looking at each other while we stroked, him looking at my cock almost pushed me over the edge, we were both commenting on our cocks, my cousin saying "fuck that's big" and me returning the comment.
In a moment of madness I reached over and I grabbed his hand to help jerk him off, he was reluctant to move his hand away which I was sad at, but then I reached a few fingers down on to his balls, only a few hairs had developed on them and the skin was smooth, I heard him groan and as I was helping him stroke I felt him shiver and he exploded a decent amount of cum onto his stomach.

This sent me over the edge and I just exploded a big load all over my chest, he was amazed and we both lied there panting from the release we just had.

After this we cleaned up and went to sleep, this happened a few more times but has recently stopped for about 6 months.

I want it to happen again but don't know how to go about it, if someone could help me I'd love that