Jerking Off With My Sexy Fat Bro While Driving

I (gay 19m) live in rural america, so there are a lot of dirt and gravel roads. i just got back home from uni. I'm hanging out with my straight 20m best friend, who is a fat boy with a big ass and a big belly. (We've been friends since childhood, and i've always thought he was incredibly sexy. I honestly think this guy is the reason i have such an affinity for overweight dudes. )
So, a couple days after coming home, we're hanging out, driving down dirt roads, when all of a sudden, Friend pulls his nuts out through his fly. This is normal, as it is something we have done for years. it's a bit of a running joke we have going on (even though i find it incredibly hot) . One of us will text the other, saying "you're so nutty", to which the other will respond with a pic of their nuts, or dick, or both (because of this, i have so many pics of his dick nuts and butt that i jerk to regularly) So, naturally, i pull my nuts out too. We laugh, and we start talking about shaving down there. He asks to compare bushes, so we do. We pull our pants down past our butts, so we can compare dick sizes, nut sizes, bush sizes etc etc. All while driving. In my mind, i'm going crazy. this fat motherfucker turns me on so goddamn much and he's got his dick out right in front of me. I was unbelievably horny and trying my best to not get hard. Until, he changes the subject again. We start talking about different ways we would jerk off, what we would jerk off to, who we would fuck, etc. By now, we get even more comfortable, and our pants are off completely! So here we are, driving around in rural illinois half naked together, showing each other how we stroke our cocks. So, he's in the middle of showing me how he grips his dick when he jerks it, and he stops suddenly, and says "damn, i almost nutted, haha". I laugh about it and say "haha, but as long as you clean up, i don't care if you jerk off rn". Almost instantly, he reaches in my glove box to get napkins and starts stroking it hella fast. I'm watching him do it, and he knows. It's like he's putting on a show for me. I'm watching his belly jiggle as his strokes his length, and i'm watching his short thick cock glisten with precum. "fuck it" i say, and i pull over and start jerking off with him. he cums first, he moaned so damn loud as he shot 6 times. I watched his nuts expand and contract as he squirted cum all over his fat belly. I didn't last much longer. afterwards we clean up and kept driving around. this is a moment i will cherish for forever!!!.