John Cena busted out a ring IN THE RING … popping the question to fellow WWE superstar Nikki Bella — and like her brother-in-law, Daniel Bryan, she said, “YES! YES! YES!”

Cena whipped out the massive Tiffany’s diamond after he and Nikki beat up The Miz and Maryse in a co-ed tag team match at WrestleMania 33.

Here’s the thing … Cena didn’t use her “ring name” — he proposed with her real name, “Stephanie Nicole Garcia-Colace” — leading most people to think the proposal was real and not a scripted bit.

John and Nikki have been dating in real life since 2012.

After the event, Cena tweeted about the proposal.