Mike Tyson REMARRIES Wife In Surprise Vegas Bash

For the second time in two years, Mike Tyson said "I do" to the same woman ... in Las Vegas ... but this time, the "wedding" was MUCH more of a surprise.

Tyson and his wife Lakiha invited hundreds of friends to a joint birthday party they threw for each other at the M Resort ... but the b-day party was merely a cover for a secret vow renewal.

After the guests arrived to the party, the couple disappeared ... only to re-emerge behind a massive curtain ... which dropped to reveal both Mike and Lahika dressed in wedding outfits.