Halsey Backs G-Eazy's Claim He's Just Friends with Demi Lovato

G-Eazy has NOT jumped to dating Demi Lovato after his split from Halsey ... and that's coming straight from his ex, Halsey.

We got her Thursday at LAX, and had to ask her about the speculation G's hooking up with Demi. There were reports they hit up a Hollywood club last weekend. Even though that turned out to be false ... the rumor's taken off.

Halsey, who announced the breakup from G-Eazy earlier this month, says NO CHANCE. He denied the Demi buzz at the ESPYs, and his ex is fully backing him.