What will those moans be that i hear in the middle of the park?

Today is finally friday and i can go to work a little later. i get up early and take the opportunity to run for a while in a park near my house. when i reach an area covered by a tarp i begin to hear some moans. curious i go to see what happens and my cock gets hard to see how they fuck a guy's ass wildly. they know i'm there and not only do they not care if i look, but that makes them even more horny. they let me record them and enjoy watching that boy's mouth fill with cum.