Miley Cyrus -- Post-Patrick Schwarzenegger Life Is ... Kissing Everybody

Miley Cyrus' mouth is open for business and she put it to good use Thursday night ... locking lips with anyone she could get her hands on.

Miley was out at a party in Los Angeles where she sucked face with supermodel Frankie Rayder and fashion photographer Mert Alas. Even Cara Delevingne got in on the action with a quick snuggle.

Didn't take long for Miley to slip back into single life -- as we told you, she and Patrick Schwarzenegger broke up earlier this week.

Miley's mouth is making up for lost time.