This happy mom thought she was in town to celebrate her oldest daughter's birthday over Valentine's Day weekend, but little did she know that she'd actually be the one getting the gift of a lifetime.

"Are you kidding me? Are you kidding me? Don't mess with me, Lisa!," mom Judy Minunni, of Buffalo, New York, shouts at her daughter, Lisa Englert, of Erie, Pennsylvania, in this hysterical moment on caught on camera.

Englert handed her mother an early Valentine's card that read, "Happy Valentine's, Grandma. I can't wait to hug you this fall," which Minunni initially took as a cruel joke because she's been dying for grandchildren ever since her daughter walked down the aisle four years earlier.

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However, what came next was nothing even Englert, 30, could have planned for.

"My mom is a very energetic person," she told ABC News. "We had a feeling she was going to freak, but I don't think we expected it to be anything like that."

Once her mother had a moment to process what was happening, she couldn't contain herself. Minunni practically exploded with joy, hopping up and down, screaming and shaking her fists in the air in excitement.

"She has a lot of love to share and she's just been waiting to share it with somebody else," Englert explained of her over-the-moon mom.

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It's hard not to smile when watching Minunni's hysterical reaction as she goes insane over the baby news, bouncing off the walls, barely able to keep herself from tackling her daughter in pure delight.

"It's crazy, this whole thing is so crazy," Minunni, 58, said. "Every step about this has been so exciting. It gives you a reason to get up in the morning."

The new addition to the family is expected to arrive Sept. 30, and although they're keeping the sex of the child a surprise, Englert says her mom has "already filled up the baby's closet with gender-neutral stuff. She's just so excited."