paintbrush dick
A paintbrush dick is when your willy is barely hard. It’s not stiff enough to do the job, but it’s too proud to stay soft.
My buddy tried to impress a girl and it looked like he was trying to paint a wall with a limp brush.
He said he had a full house, but it was just a paintbrush dick and a sad chin.
I told my brother his pecker was a paintbrush dick, and he threw a chair at me.