Quick Definition: The PUA who gets to pick the target. Also refers to the guy you’re trying to hook up with a girl. (Not to be confused with Primary GF, which refers to the artist’s primary girl that he’s closest with.)
A general rule of thumb that most PUAs follow is “Whoever opens the set, owns the set.” Thus, the guys who opens the set gets dibs on which girl to go after, and his wings can either game her friends or handle the obstacles until the primary secures a close.
The term primary can also be used to refer to the guy that a PUA or group of PUAs is trying to get hooked up that night. For example, one PUA might owe a favor to another and give them first pick when it comes to girls, even in sets that he opens. Then he actively works to get that PUA laid. In that case, the guy who is owed the favor would be considered the primary.
Ryan can be the primary tonight, since it’s his birthday and I want to get him laid.
Source: Nathan PUA (NYC Lair Chief)