When a rather unattractive man is dating an attractive female, an explanation could be because he has an unusually large penis AKA Slow Dick. Similar to a mentally challenged person having unusual strength (Retard Strength) it is often said that a mentally challenged make has an unusually large penis (Slow Dick)

When you eat dirt for the first time and leave your family to build a shack in the woods

A dick that erects like an old swan. Similar to "Snail dick" it is crooked and bent like a swans neck or a snail's back. Those who have SLOW DICK tend to have crusty, salmon smelling smegma.

Slow dick is usually used as an insult unless one takes pride in having one. It can also be used to describe a male's genitalia.