The act of calling your friends in an attempt to set a time to have sex at the same time as each other. This act builds lasting friendships and bonds as each person has sex knowing that they are having sex at the same time as their friends. This act can be done alone (Hand Solo) if a partner is unavailable.
Bob emailed all of his friends to Synchronize Watches at 8:30 tonight. My wife is on the rag so I will be going Hand Solo.