Ali Larter, who starred in NBC's 'Heroes,' is going to become a mother of two. The 38 year-old actress and her husband, Hayes MacArthur, who are already parents to a 3 year-old son, Teddy, are preparing to welcome their family's newest addition in the not too distance future.

Ali Larter
Larter revealed the pregnancy news while appearing on Jimmy Fallon's 'Tonight Show'

Larter revealed the exciting pregnancy news while appearing on Jimmy Fallon's 'Tonight Show' to promot her new series 'Legends,' she showed off to the host and studio audience her growing baby bump, which was under a curve-fitting sparkling dress and black blazer.

More: See all our Ali Larter Photos Here

Fallon seemed over the moon for Larter, cheering and clapping for her before kneeling down near her stomach to talk to the unborn baby. "Hey buddy! I can't wait to meet you! We're going to be friends." he said.

Prior to appearing on the show, the 'Final Destination' actress teased her Twiter followers by tweeting, "Backstage at @fallontonight I'm going to surprise @jimmyfallon with some big news!"

Larter's last appearance on a Jimmy Fallon chat show was back in 2010 when she was carrying her first child, and she jokingly explained that getting pregnant once again was directly linked to visiting the show.

More: Jimmy Fallon Talks "Craziest" Year Ever And Parenthood Being "Exciting"

"[Three years ago] I came on and I was pregnant and it went so well, and I said to my husband, 'I'm going on Fallon, you know what that means - gotta get pregnant!' " she said.

Ali Larter
Larter and her husband, MacArthur, are parents to a 3 year-old son, Teddy

"It's so exciting. It's such a scary time and I've been trying to hide it as much as you can, and when you're in the public eye it's really scary in the beginning," she added. "I was still shooting my spy drama . I had to be a covert spy in my real life, too, so I'm wearing blazers and push-up bras and everything you can do to distract."

Congratulations to Larter and MacArthur.