To prove they can focus on two things at once.
One can... "Get Hard"
The bond matures.
How they process things.
Two test tickles.
Because it said concentrate.
Square eyes
They prove men can concentrate on two things at once.
He jogs home after his vasectomy.. Fairly old, vasectomies may not be so bad any longer.
Inward
The matches are made for adults, but kids constantly grab'em and play with them. The situation is quite opposite with breasts.
They were originally intended for children but it's the men who play with them the most.