A birthday celebration becomes a viral pregnancy reveal.

FOX's Krystin Goodwin has the details:

It may just be the best birthday present ever. Hillary Hinrichs of Columbia, Missouri, surprised her entire family, announcing her pregnancy while celebrating her mother Terry's birthday.

The mom to be handed the birthday girl a cake, on it was a family joke...The text: "Happy Birthday Ya Stupid Lookin' Grandma."

It took her a moment, but when her mother works it out, she is brought to tears...

Members of the family rush to give hugs, lots to celebrate. Hinrichs shared the moment on Facebook. She says she is expecting a baby girl in November.

I'm Krystin Goodwin, FOX News.

Follow Krystin Goodwin on Twitter: @KrystinGoodwin