Sean Parker Pays Millions Over Environmentally Unfriendly Wedding

Sean Parker's massive $10 million wedding was a MENACE to sensitive fish and plants in Big Sur ... and he NEVER got proper permits for any of it ... so claims wildlife officials who have settled with the Facebook billionaire for $2.5 million.

Parker struck the agreement with the California Coastal Commission after agents were tipped that he built a wedding site the size of a massive movie set in an ecologically sensitive area -- cabins, dance floor, staircases, waterfalls -- all without permits.

By the time coastal officials investigated, the structures had already been built ... but they let the wedding go on as scheduled. The 33-year-old Parker tied the knot Saturday with singer-songwriter Alexandra Lenas.

After the shindig, the commission had the structures taken down with no damage to the area ... they also said Parker was super cooperative.