One quiet afternoon, I walked in on Maxx as he was working out. I didn’t so much as “randomly” walk in, but had already heard his muted grunts-of-effort from outside the door. I walked in and told him how great he looked, and I asked him if I could take a closer look at his progress. My hands found their way to him. I made sure to get a good feel—at this point, there was no need to play coy with my boy, or hide behind excuses. I pulled my old jock out from my back pocket and asked him to try it on. This hit something within him—he acquiesced immediately, dropped his sweats right there in front of me, and put on his dad’s old jock. As always, my intuition was spot on—he filled out the jockstrap perfectly. I made sure to let him know, both verbally, and of course, physically, how beautifully he fit in between the straps. I grabbed his thighs, and played with his firm, full ass cheeks. I had him turn around for me, his sack and his shaft left a perfect print on the front of the white jockstrap’s rough fabric. I noticed how the pouch began to stretch, my son’s cock swelling up at my touch. I teased a bit, letting my finger run along it through the fabric. I let the head of his cock poke out at the waistline, and then I slowly pulled the fabric down to reveal his growing dick. I took hold of it, examining how it stiffened for me. My boy has a beautiful shaft; I gave it a few good strokes, then went in for a whiff of his scent. His balls smelled of masculine sweat, delicious enough for my mouth to instantly drop open and breathe it in through my mouth. I let my tongue flicker around the head and staff. He responded to my oral assault with adorable little moans of pleasure. I took off my shirt and had him turn around; there were more tastes I wanted to take. Again, Maxx let me know the pleasure was mutual via moans and coos. I took off my jeans and freed my own rigid dick from its confines before diving back into his cheeks face first. I stroked my cock as I ate him out. And with that taste, I knew—I needed to be back inside him. I stood up and pointed my stiff meat right at his waiting puckered hole. Tight as he was, his hole invited me in with eventual ease, like yielding butter. Soon I was balls-deep and pounding him up against the wall. I fucked him there for a while, then I had him get on all fours on the floor. I steadied myself by gripping the strap of his jock and re-entered him from behind. I was going in even deeper now; the both of us grunted and groaned together. I could feel my balls begin to build to a great orgasm, and I thought, I’ve cum inside him plenty of times before. This time, I decided to paint his cheeks with my explosion. After treating his rear like a canvas for my seed, I slid back in and rested on his back, letting the last of my pleasure drip-feed into him. My boy had milked another good load out of his dad, and with my old jock on, I thought he looked great doing it.