"I'm shell shocked," a source in Carey's camp tells PEOPLE. "As far as I know, they are happy together."
Music mogul Russell Simmons said he didn't know about the nuptials ahead of time, but sees why the pairing works. "Whatever makes them happy," he said Friday. "They have a lot in common and should have a lot of fun together."
Even Cannon's family was surprised by the move. "It's crazy right! We're definitely happy. Well wishes!" Cannon's brother, Gabriel, tells PEOPLE. "I'm trying to be like him and I love him very much."
Another insider says the newlyweds didn't know each other before Carey's video shoot for her song "Bye, Bye" in the Caribbean on March 26. "Nick was cast as the romantic lead and was flown to Antigua where they met so basically their [romance] started during the shoot," the insider says, adding, "She's very into religion and Nick is very into religion. That's something they bonded on."
Whatever their connection, Jacob Arabo, who created the diamond sparkler that the actor gave the singer as an engagement ring, tells PEOPLE that his friend is in love with Carey.
Still, others seem more dubious of the whirlwind romance.
"This is what Nick does; Nick is such a sucker for love," said a source close to Cannon. "He falls in love so quick."
Adds another Cannon insider: "We all thought it was a joke, but he's been impulsive before. He's a mini mogul but still young and maybe this was a crush that went too far.
"Well see. He takes awhile to come down from the cloud."
Reporting by MARY MARGARET, JESSICA HERNDON, and JEFFREY SLONIM