VIDEO: Utah couple keeps pregnancy a secret for 9 months, watch grandma's epic reaction

(KUTV) A Utah couple had this crazy idea when they found out they were expecting their third child - what if they kept it a secret for nine months?

“I was skeptical that we could do it,” Tannin Pease of Roy told KUTV on Tuesday night. “That’s not even possible. There is no way we can even do that.”

But his wife Katie Pease convinced him they could do it.

On Feb. 19, Tannin invited his mom over to visit. They said they had a big surprise for her. She walked in the house and saw her daughter-in-law standing in front of her at nine months pregnant.

“Oh congratulations ... wow,” a clueless and speechless mother-in-law says in the video posted on Facebook.

As mother-in-law Carolynn Pease reaches in to put her hand on Katie’s belly she says, “Wow, this is so cool.” But she has no idea that the surprise is just beginning.

“Guess what? We are going in to have the baby tomorrow,” Tannin tells his mom. Suddenly her excited face goes blank with shock and she throws a bag on the floor.

As Tannin laughs at his speechless mother, she just keeps repeating “what?!” as she braces herself against the stair railing. They tell her it’s a boy.

Then out of habit she asks the obvious - “how long have you known?”

The couple casually replies “oh about 9 months.”

While some close family and friends were able to guess the couple was pregnant, they completely surprised Tannin’s mom and most of his family.

“She was just almost speechless, which is nearly impossible for my mom - she always has something to say,” Tannin said.

Many may ask, how do you pull something like this off, especially when you are regularly in contact with your friends and family.

"A lot of people were flabbergasted by it," Tannin said. "People are like what did you do? Hide her in a closet for 9 months?"

He kept it a secret from his aunt, uncle and grandma. Nobody on his side of the family knew except his dad, and that was quite a while into the pregnancy.

"It was a little bit of hard work and it definitely paid off in the end," he said. "My siblings were the most surprised."

Tannin said he had to come up with nine months worth of alibis for his wife and a lot of excuses. Keeping the news from his mom compared to other people was a bit easier because his parents lived in Montana. However, that didn’t mean it wouldn’t require some creative thinking.

His parents Skyped with them every other week. So Tannin would make sure Katie hid off in the background and every time they talked, they would bring the two grandchildren up and keep the focus on them. If Katie needed to make an appearance, they would just show her face.

One day his dad was coming through the area for a business trip and there wasn’t any way they could keep it a secret and not meet up with him. So he found out and was in on the idea of keeping the secret for Carolynn. The dad helped arrange things to have he and his wife fly in and get together for Carolynn’s birthday, which happened to be around the time the baby was due.

She was so shocked, and told her son that she is still trying to process everything.

“I haven’t had time to prep or shop for the new baby,” Tannin said she told him, but he added that she said this was "one of the best birthday presents she’s ever had.“

Katie explains that initially it wasn’t easy, but after about four or five months they just decided to see if they could take it all the way. A lot of her family knew because they had seen her in person in the past five months, but they were told not to tell anyone else.

The couple had complications with pregnancies in the past, so they were used to holding out telling people they were expecting until they knew everything was OK. This time they just figured they had already kept a secret for half the time, so why not go for it?

“We just decided we weren’t going to tell anyone until the end of it,” Tannin said.

The couple got a lot of strange looks from people near the end, but most people didn’t ask any question because it’s socially not acceptable to ask about if someone is expecting or not, the couple said.

Comedian Brian Regan had good advice on this question. He said if you are ever in doubt, “I think the rule is don’t guess at that, ever, ever, ever, ever, ever, ever, ever, ever - but I didn’t have enough evers memorized, so I said, when’s that baby due?”

The rule was simple for the couple. Katie said unless someone didn’t specifically ask, we didn’t tell them.

“People would just be making quick glances to my stomach, I could tell they wanted to ask, but they didn’t -- because it’s not polite to ask.”

They took a number of precautions, including adjusting their Facebook settings so if someone tagged them in a post they couple would have to approve it before it showed up anywhere. When the couple would meet with close family, they would always come up with an excuse for why Katie wasn’t able to make it, everything from having a late night with their two other kids to anything else that would get her off the hook for not being able to show up.

Another tactic was not embracing the maternity clothes.

“I wore baggier clothes,” Katie told KUTV about how the couple was able to keep the surprise a secret from most people. “I tried not to wear clothes that were too obvious. We avoided attending events that weren’t super important so we wouldn’t show off the pregnancy.”

Toward the end there were a lot of people who looked like they wanted to ask but didn't say anything

“You don’t want to ask because you think ‘what if I get it wrong?’” Tannin said.

A week before the couple made the announcement on Facebook Live, Tannin built up anticipation and told people he would be making a major announcement in a week and that people should tune in.

While the couple was in the hospital and Katie had and IV in her arm, they made their formal announcement to the rest of their friends and family. Hours later a healthy baby boy named Saul was born on Feb. 20 at 10:09 a.m., weighing in at 7 lbs. 7 oz. and 20 inches long.

Katie said the reaction has been mostly excitement for the couple. She thinks the whole thing was fun and if she was on the receiving end of the news she would prefer to get the news this way.

The anticipation for keeping the surprise was just so fun and kept her motivated to keep it a secret, she said.

“I was just too excited to surprise everyone,” she said. “They get the surprise for the baby and they don’t have to wait 9 months. All of the sudden the baby is there. If someone did that to me, I would love it even more if I didn’t have to wait to meet that baby. I’d like to meet them instantly; I think that’s what makes it so great.”