GUY & DELTA'S FLIRT FEST!

THE COACHES CAN’T KEEP THEIR EYES OFF EACH OTHER

They’re rival coaches on the hit show, but behind the scenes, Guy Sebastian and Delta Goodrem’s close relationship is raising a few eyebrows.

While in past seasons the singers have relished their friendly competition, this year New Idea has learned the former couple has grown closer than ever.

Now, an on-set insider reveals the pair’s closeness caused some serious tension backstage – particularly with fellow coach Kelly Rowland.

“Kelly got so frustrated as she couldn’t break the Guy-Delta bond and alliance,” the source explains.