I remember, a few years back, seeing a funny scene (I forget the performers involved) where the guy is shooting a POV scene and is fucking the girl's pussy fast and deep... really hot penetration that went on for a few minutes in missionary position. Then suddenly, he pulled out and didn't do anything for a few seconds, just breathing hard and not touching his cock, like he was at his limit and was trying to take a quick breather and cool off. Then he tried to put his cock back in and pounded her pussy hard and fast maybe half a dozen times - "fuck!!", pulls out, cum is already squirting out of his cock, tries to clamp it off while he tries to get her face in range - no luck, he busts his nut here there and everywhere, maybe getting just a few of his last weak spurts on her face like he wanted. He cursed up a storm of fucks and dammits aimed at himself -- he'd pushed himself to his limit, didn't give himself enough time to cool off, and just those few thrusts afterwards were enough for him to completely lose control and bust his nut before they were ready to finish the scene.
I always liked that scene... it was funny and sort of a candid blooper, but it was also hot, because the girl's pussy was just too good for him to take. I don't see that kind of thing very often. I'm wondering if people here have seen other good examples of guys trying to fuck a hot chick and fail to put the control rods in before suffering a "reactor meltdown"... one of those classic uncontrolled cumshots that are the worst nightmare of a director or male performer.