When I was in college I once went into a bathroom stall to take a dump, and after sitting down, noticed that there was a load of jizz, that was still wet and gooey, hanging on the wall next to me. Boy, that was a LONG time ago! But I still remember it turning me on and even putting my finger in it, bring it to my nose, and smelling it! I didn't try tasting it!
I'd done similar thing, on 2 occasions.
1) I found fresh cum left inside a bathroom stall in the Men's room at a local area Mall. The cum was on the floor right beneath a wall between 2 bathroom stalls.
2) I found fresh cum in my company Men's room, it's a single use one which you can lock it while you're in there. The cum was on the floor next to the wall opposite of the bathroom stall, at early morning hour, around 8:30AM.
Instead of putting my finger in the cum, I took a few sheets of toilet paper and roll them up, then I dipped it in the cum and pulled it back out and looked to see how it was dripping. If too watery then it's not cum. Both times, they're real cum due to the slow dripping or viscosity of the cum itself. Once I knew for sure it's cum, I re-dipped the toilet paper in one more time and brought it up to my nose to get a good sniff and got a good smell of it, the musky smell of the cum gave me a semi hard-on. I threw the toilet paper in the toilet, washed my hands and left. I found it very erotic too see someone's cum, either dry or fresh somewhere that men would unload his cum and leave it there.
However, one place I do not get turned on is when I found cum in Adult Book Store video arcade. I did get blow jobs and shoot my loads there, many times while I was young, horny and single.