play it cool
To pretend you're not as anxious as you really are; usually used in terms of dating, deals, or any life-altering events.
Dude let HER call YOU, it's only been two days-- play it cool.
Play it cool
To try to act normal or to blend in with the environment/other people. This is usually to prevent getting into danger or trouble.
Example 1: Hey, we gotta play it cool, we're in gang territory.
Example 2: If you don't play it cool you might get in trouble.
Example 2: If you don't play it cool you might get in trouble.