How long a man lasts depends on several things. Since sex is about 10% physical and 90% mental, how long a person lasts is mostly dependent on the level of arousal, which is largely mental. Ask yourself how long it would take you to get there if you were having sex in the most romantic fantasy you could muster? Not long. Would that depend on your physical attributes?
Penis size has nothing to do with how long we can last.. Nothing whatsoever.
haha when I first saw this I was like well..How could a guy give a description of both big or small? If I have big I can't speak for the small guys hahaha. I'd say no it has no relation. There are times I can go for over an hour and a half and sometimes when it's really hot and heavy it might be only 20 minutes. It's just how aroused you are and if the guy can keep his mental focus concentrated. And I'm speaking from the Bigger side of the fence haha.