pop your collar

When you pop your collar, you reach up to the shoulder of the correspoding arm or across the chest to the opposite shoulder, and, using your index finger and your thumb, you pull up on the shirt and let it "pop" down, hence the phrase. It is perfectly acceptable to pop your collar whenever you have accomplished a great, admirable feat, such as busting a sweet dance move, pwning the entire opposing team by yourself, or to establish your extremely high playa factor.