Get real! informal slang
The slang is often used as an imperative.
Used to advise someone to quit being silly or irrational about something and to start thinking about it in a sensible way, or being realistic.
Hey, get real! You just can't afford to pay that much money.
"She thinks Tim is having a crush on her" - "OMG, get real! He already has a girlfriend".
The slang dates from the second half of the 1900s.