David Guetta Not Engaged to GF Despite Her Rocking Huge Diamond Ring

David Guetta and his GF are not walking down the aisle anytime soon -- or ever, really ... but the DJ did give her that giant diamond ring she's rocking. Let us explain.

Sources close to the couple tell TMZ ... the EDM superstar straight-up doesn't believe in marriage -- anymore, anyway -- and that's why he and actress Jessica Ledon are NOT engaged. As we reported ... the couple was hanging on Miami Beach this week and her big ol' ring drew a lot of attention.

And, the story behind the rock? We're told it's a promise ring David gave Jessica last year -- a promise to "love and commitment" ... but NOT a promise to walk down the aisle.

As you know, David got married once before ... in 1992 to Cathy Guetta. They divorced in 2014.

David and Jessica have been dating since 2015 and, obviously, still going strong.

Nuptials. They ain't for everyone.