Credit: Kevin Mazur/

What, no diamond-encrusted butterflies or mink teddy bears?

First-time parents Mariah Carey and Nick Cannon had a surprisingly low-key baby shower in Beverly Hills on Sunday evening.

Held at the rooftop Conservatory Grill at Montage (a boutique hotel), the bash "was very elegant and not too over the top," an eyewitness tells

Pregnant with a twin boy and girl, Carey, 41, and hubby Cannon, 30, arrived in their Rolls Royce Phantom and greeted guests upstairs -- where the black-and-white eatery was decked out with pink and blue flowers and balloons.

Well-wishers checked out the panoramic city views as they munched on appetizers and toasted with champagne.

What did the superstar couple get from their pals? Two elaborate stuffed giraffes, gorgeous baby blankets, luxe clothes plus books and bath toys.

"Mariah and Nick seem very excited and anxious about finally having their babies," the party witness tells Us. "He was doting on her the entire night, rubbing her back and getting her water. He really takes care of her and wants to make sure she is comfortable."