A game where 2 straight men stand in front of each other will completely naked and stare at each other, the person who's penis moves first loses, can go on for hours and is sometimes called a game for horny people
Phill went to toms house and ended up winning a game of stale penis.
A sock that has been over the years filled with semen cum or in other words splooge. Due to the fact that it layed there soaking and drying up the cum it has become stale and hard over time (just like my relationship with my wife)
Your Mom: hey sweetie I found this sock in your room, its really stale what did you do to this