Jennifer Lopez buys Casper Smart a birthday truck Jennifer Lopez and Casper Smart Jennifer Lopez celebrated her dancer beau Casper Smart&#...

Jennifer Lopez buys Casper Smart a birthday truck

Jennifer Lopez and Casper Smart

Jennifer Lopez celebrated her dancer beau Casper Smart's 25th birthday on Friday with an intimate dinner party – and quite a big surprise.

"Jennifer had planned a fun day to celebrate Casper's birthday," a source tells PEOPLE. And the day began with a four-wheeled birthday present: a customized white Dodge Ram truck.

Lopez "knew that Casper really wanted a truck, and Casper was very excited about the generous gift," says the source.

Lopez also Tweeted: "@BEAUcasperSMART 'Beau has a birthday we're so glad we hope it[']s the happiest Birthday Beau ever has!' #singingtweet. HAPPY BIRTHDAY BEAR!!!"

After a shopping trip and lunch in Beverly Hills, the couple continued the birthday celebration with a fun dinner at Cecconi's in West Hollywood.

With a group of friends, they enjoyed Northern Italian comfort food, including pasta, fish and wine in the restaurant's private Butterfly Room.

The birthday boy even brought his present along for the celebration. "Casper was so excited about his new truck that he decided to drive it to dinner," adds the source. "She was smiling about Casper's excitement."