Heather Matarazzo and Carolyn Murphy attend the 20th Annual GLAAD Media Awards at Marriott Marquis on March 28, 2009 in New York City. Credit: Dimitrios Kambouris/WireImage.com

Welcome back to the single world, Heather Matarazzo.

After over five years together, the actress, 29, has parted ways with girlfriend and fiancee Caroline Murphy, a close friend tells Us Weekly exclusively.

Back in July 2011 -- when same-sex marriage was legalized in their home state of New York -- the Welcome to the Dollhouse star and Murphy revealed that they'd been engaged for three years. (They had originally planned to wed two year earlier in California, but the passing of Proposition 8 changed their plans.)

Although the pair had originally talked of a spring or fall wedding with 200 guests -- and even baby plans -- "they've been on the way to ending things for a while," explains the pal of the "mutual" split, adding that the twosome have been living in separate states "for some time."

Continues the friend: "In the end, they realized they were missing the spark. They had been best friends for so long, it turned out they loved each other, but they were no longer in love."

Matarazzo is "doing good," the pal says. "The relationship made her learn a lot about herself and she is thankful for that."