The actor has been with journalist and photographer Sandra Delgado since 2001, and even though he wears a ring on his wedding finger, he reveals they are not technically married.

The 39-year-old, who shares three sons with Sandra, decided to try and rectify the issue while on vacation in Sin City, because he thought it would be fun to exchange vows at one of the many chapels with an Elvis Presley impersonator conducting the ceremony.

However, his big romantic gesture backfired when Sandra laughed off his suggestion.

"I'm married but I never got 'married'," Wagner explains to U.S. talk show host Jimmy Fallon. "I've been living with my wife for 15 years, we have three kids, and we never got married properly. So I thought... they said it's kind of cool, there's this Elvis Presley thing (in Vegas), and I proposed... She said, 'No, this is ridiculous, what are you thinking?'"

The failed proposal wasn't the only bad memory Wagner has of his visit to Sin City - he was also left out of pocket after failing to get to grips with card game blackjack.

"I didn't understand it; I'm still trying to figure it out," confesses Wagner, who hails from Brazil, where gambling is illegal. "It's like, really different... I tried to gamble a little, but I just didn't understand the rules... It didn't work well for me. They said the easiest one was the blackjack, but I just didn't understand it... I lost $60!"