What happens to the nerves during erection. Do they stretch, lengthen?

What happens to the nerves during erection or manual stretches. Do they stretch or lengthen with the penis elongating with it? Or does it just slide back staying behind? I was reading an article about nerves stretching in arms and legs (which don’t actually extend as does the penis) and it states that nerves don’t actually stretch.

Nerve Stretching - Core Concepts.