This is something that I've been curious about for a while. I've noticed that, under the same conditions, men will develop erections of varying hardness (I'm laughing as I type this so seriously). For example, I noticed when I was with my ex that when he would get hard, I could still give him a squeeze and my fingertips would press into the flesh as if it were still soft. With my boyfriend, when he's at attention, he gets as hard as a rock.

Is there any explanation as to why some men get harder than others? Does the spongy tissue in the penis just expand more for some men than others? Do hormones have anything to do with it?

I know it's probably a stupid question, but I wonder about it...because I have no life.