Actually I think the camera angle was a bit of a giveaway, not the best fake cock/ejaculation scene. The semen also look a bit off. I think the dead giveaway is the position and immobility of the cock, pay attention to the leg, the cock seems to grow out of his lower belly instead of his groin.
Anyway I appreciate a well made scene, even if it's fake. There are a few men in the world who cum a ton of semen, or can ejaculate multiple times in a session. Even I had 3 or 4 ejaculations within a evening/night, about 3 times so far. Somehow all the stars lined up, I was in the right physical and emotional state, the woman was right, the hotel room, everything. So I allow some benefit of doubt/suspension of disbelieve. I.e. I can "know" that a scene is fake but "believe" (pretend, if you will) it's real for the purpose of enjoying the vid. How else could I watch tentacle porn?
There's this sub-genre of "baby-making" (typically a variant of the harem genre) that has the guy ejaculate more than 10 times in a single continuous scene (not a continuous shot, of course). I guess they are fake too. But honestly I have not been scrutinizing the video to find definite proof of fakehold. Is there a tiny tiny chance a guy with lots of practice and self-control and maybe drugs (Viagra?) can cum that many times?
Another possibility is that it's actually filmed over multiple days (so each ejaculation is real and/or with stunt penis) and edited together to make a single scene.
BTW,
@leebar you don't mean to say stunt-penis in your post. A stunt something is still a human, real. You meant to say "prosthesis" if it's something (say silicone or foam) grafted or attached to the actor, or worse case: "prop" if the crew didn't even bother to do that and just use camera angle to compose the shot. Which might be the case with the GIF posted by
@kessari .