John Cena and fiance Nikki Bella kiss for the cameras at MTV Movie & TV Awards

Save it for the wedding!

John Cena and fiance Nikki Bella are head-over-heels for each other -- as evidenced by red carpet photos from the MTV Movie & TV Awards on Sunday night. The couple looks completely smitten in a series of full-on makeout shots for the cameras!

Nikki's diamond ring was on display as she and her soon-to-be husband smooched repeatedly, breaking up the kisses to smile at each other.

Nikki stunned in a black maxi with a thigh-high slit, but John's look was questionable: His bold blue-and-green jacket, clashing red tie and ill-fitting pants weren't his best look -- but to be fair, it's not so easy to dress his 250-lb frame! (We're not letting him off the hook, though. He's been on his style A-game before, and this just wasn't it.)

John proposed to Nikki in early April at a WrestleMania event. No word yet on when they'll wed -- but fingers crossed it'll be by the end of 2017!