Andy Samberg and Joanna Newsom attend the Film Independent Spirit Awards at Santa Monica Beach on February 23, 2013. Credit: Alberto E. Rodriguez/Getty Images

No joke -- Saturday Night Live alum Andy Samberg is getting married! A rep for the actor confirms to Us Weekly exclusively that the 34-year-old funnyman is engaged to his girlfriend of five years, singer-songwriter Joanna Newsom.

Samberg was smitten with the 31-year-old musician even before they met through mutual friends. "He liked her music and would go to her shows," a pal told Us last year. "He had the biggest crush on her."

Newsom is equally enamored of her beau. "She respects what he does with his songs," the friend said, referring to Samberg's quirky tracks ("I'm on a Boat!") with comedy troupe Lonely Island. "She's so proud of everything that he has accomplished."

The happy couple have kept a relatively low profile over the last five years, preferring quiet date nights at home to all-night parties. Added the pal: "They have great chemistry."