Funny you guys are talking about this. Been thinking about it recently. From personal experiences, theres definitely nothing more embarrassing than having an extremely good body, and having weak dick function/ pfs dick. women are always so disappointed, and the whole thing is just frustrating and old. so like cdsnuts says, its definitely something more brain related.

I do alot of my sets and reps to muscular failure though. It doesnt seem to hurt me. Or maybe it is? I like the way it feels.