How do the men in porn movies sustain their erection for such a long time? Never seen my husband sustaining it for a long time like them!!

This is the beauty of entertainment! ! Nothing is real. As mentioned by the others they are same shots repeated over and over from different angles. Some movies are even made over a few days and pieced together to look like 1 hell of a session. Please do not read too much into them and enjoy them only from the point of view of entertainment.