What we're talking about here is the result of a good old fashioned deep thrust. This is when the mans nest is mingling with the womans after a full insertion - and I mean to the hilt.
1. Steve shaved his man area so there will be no hair on hair for him for awhile - only skin on hair.
2. I tripped on a loaf of bread at the grocery store and accidentally went hair on hair with the stock boy...
3. The only way my brother can achieve hair on hair is to get a running start.