I used to spy on my dad nearly every day in the morning while he was getting ready for work before I left for school. His morning routine including the usual, shitting, shaving, and taking a shower. But it also included something else, jerking off on the toilet. He had his routine, and watching him was my routine.
I don't remember how I began spying on him, or what triggered me to become curious, but his master bathroom had a rather large opening at the bottom of the door (between the floor and the bottom of the door). You could see a full foot under the door, and the toilet was right next to the door. Not only could I get the idea of what dad was doing in there, but I could sometimes get to hear him too. I'd listen to his heavy breathing, especially as he got close to cumming. He wasn't a moaner, at least not while beating off.
I always knew when he was getting closer to cumming because he would spread a towel down in front of the toilet. I often could get a clear enough view that I could see his load covering the towel after he shot it. After a minute or so I'd see him fold the towel up (not to drip cum I'm guessing) and get in the shower.
The best part was when he left for work. He would put his cum towel in the bedroom hamper, or sometimes straight into the laundry room and after he left I'd take the towel back to my room and jerk off with it, smelling his cum and licking it (if it hadn't fully dried yet). Sometimes dad would be in a hurry and he'd leave for work just 10 minutes after jerking off on this towel, and those times were the best, his cum would be fresh. Dads cum wasn't thick, from what I could tell, but he shot a lot. There would be drops all over the towel, not a big load in one spot like I tend to shoot.
I'd keep his used towel in my room for a few days, and beat off with it several times. I loved thinking about our cum mixing together, father and son. I also have to say that his cum smelled just like mine. I never got enough of a taste to really compare in that way, but just being that close to it made me shoot my load within a couple minutes. Licking the wet drops of cum that made me was the hottest thing ever.