This phrase is used when you catch a person in an outright lie. Catch a person lying to you.
Me, "Don't play yourself, I know you took the last donut!"

Other guy caught taking the donut.... Lolololol
by Old Mom January 7, 2017
A phrase used to warn somebody not to reveal weaknesses that they might have such as planning their own surprise party or eating a McDonalds after working out. Dj Khaled is the spokesperson for not playing yourself.
-"I miss my bitch so much, I want her back homie."
Reply: "Nigga you broke up with her. Don't ever play yourself man."
by Keith Conlan September 11, 2016