Surprise! Mom of 5 Tells Husband She's Pregnant Again On His Birthday Cake

"If it's a boy, I have all the clothes. If it's a girl, I'm going to need a big baby shower," said the 35-year-old mom with five sons, laughing.

A man's birthday turned into a celebration of another birth -- when he found out that he was going to become a dad for the sixth time.

During a birthday dinner for her husband, Riverton native Christy Allred asked restaurant staff to ice "Thanks For Knockin' Me Up!!" on a plate beside his birthday cake.

As the plate was brought out, a waiter caught the whole surprise on camera.

Speaking to InsideEdition.com, the mom-of-five said she couldn't be happier when she learned that she was pregnant again -- especially because she found out on her husband's 35th birthday.

"As soon as I found out, I wanted to call him and tell him, but I wanted to make it memorable," Christy said. "I took to the internet to find the ways other women have told their spouses. I saw a phrase [written on a cake,] and I was like, 'Yes, I'm doing that!'"

Read: Mom-To-Be Baffles Her Grandparents By Using 'The Whisper Challenge' To Announce Pregnancy

She invited her husband, Kelly Allred, to dinner at their local Red Robin, where her brother once worked and the staff was familiar. She called the restaurant to organize the surprise and the plan was in motion.

After their meal, the waitress brought over a cake with the words written in chocolate on the plate.

"Yeah, five times," her husband of 15 years said in the Viral Hog video when he read the cake. It was clear Kelly was confused, and unsure about the fanfare until he realized his wife was trying to say "thank you" -- not for the boys they were already raising, but for the one that is on the way.

Finally, Kelly's jaw drops. "Are you serious?" he was heard saying.

When they told their five sons five days later, they sat the boys down on the couch from oldest to youngest and Kelly asked: "Is there room for one more on that couch?"

Their middle son, 10, smacked his head in surprise. Christy told her youngest son, 5: "You're going to be a big brother!"

Christy told IE.com that they had their oldest child, who is now 14, when they were almost 21 years old, and is excited to still feel young and refreshed as they prepare for their sixth child due on December 2.

On top of giving birth to five healthy boys, Christy said she also suffered five miscarriages: "We didn't want to get them too excited only to have another miscarriage. They do feel like they've lost siblings. They're young and they don't really understand everything about it."

She said two of her pregnancies were lost early on, within two months of becoming pregnant, but the three that have survived over four months have been the most traumatic: "I prepared them that we can hope for the best, but we can't control the outcome."

Read: CrossFit Trainer Insists Weightlifting Routine Is Healthy Even at 9 Months Pregnant

If everything goes well, Christy said they will be excited to welcome either a boy or a girl into the world, but are ambivalent as to which, even though they already have five boys.

"If it's a boy, I have all the clothes," Christy laughed. "If it's a girl, I'm going to need a big baby shower."

Watch: State Troopers Surprise 10-Year-Old After No One Came to His Birthday Party