Man Cries Tears of Joy When He Learns His Newborn Grandson Is Named After Him (Exclusive)

A heartwarming moment has gone viral after an Iowa man broke down in tears of joy when he learned that his newborn grandson was named after him.

"I didn't know how he'd react," Morgan Henningsen, the man's daughter, tells PEOPLE. "I knew he'd be happy, but I wasn't quite expecting that reaction." 

In the TikTok video, which she shared on Father's Day, Henningsen's dad gets visibly emotional after learning his grandson's middle name is the same as his first name: Robert.

"I was like, 'I just think this video is really sweet,' " she says. "At the time, most of the people [who] followed me on TikTok were friends of mine and so they knew him. I was like, 'I just think this would be kind of a fun thing to share, just something lighthearted and sweet for Father's Day.' "

But Henningsen says that once she posted it on June 16, she was "absolutely blown away" by the response from thousands on the platform.

Opening up about how the sweet moment came to be, the 33-year-old mom explains that in August, a day after son Lennox was born, her parents were texting her asking about his name. Instead of telling them, she decided to keep it a secret until they got to the hospital. 

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"My plan was to hand them the name sign and then flip it over because I knew that they would want to hold it right away," she says. 

Once they arrived, her mom flipped over the sign, saw his name and tried to "hold it together."

"[My dad] looked at her and started crying," she adds. "She started crying, and she was very happy about it because she could tell it meant a lot to him. I think it meant a lot to her, too, so everybody was crying."

Her 62-year-old dad, a retired school superintendent with "a big heart," has always meant a lot to her and her older sister. 

"I've always been particularly close with my dad," she says. "I was close with his dad as well, so I feel like he's just always been one of my biggest supporters in life."

Though she wasn't always sure she wanted to have kids, she made up her mind once she got married. "When I found out I was having a boy, I knew what I wanted his middle name to be before I knew what I was going to have his first name be," Henningsen shares, calling it an "easy" decision.

Her dad loves the emotional video, which now has over 4 million views and nearly 300,000 likes. "He'll ask me about it every once in a while," she shares.

"He's like, 'I just can't believe it,'. " she recalls, adding that her response was, "'Neither can I.' "

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Lennox is now a healthy 10-month-old baby who is "growing like a weed." Though the mom admits he's in a phase where he is apprehensive about people, including his namesake, she tells PEOPLE that her dad isn't too worried. 

"He's definitely getting used to him," Henningsen says. "My dad will call me, and it's like he doesn't even ask about me anymore. He just wants to know how's Lennox doing."

She continues, "I know once Lennox gets a little bit older they're definitely going to be pretty tight."