This young father managed to pull off the ultimate surprise after his girlfriend decided to take a pregnancy test.

In an effort to trick her, YouTuber Oscar Morales switched out baby mama Kyra Sivertson's positive strip with a negative one, later sharing the exciting news with the help of their infant son Levi.

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Taping the positive test onto the baby's onesie, Kyra was shocked to see that she is, in fact, expecting her second child.

"So excited to announce the newest member to our family," the pregnant 19-year-old wrote on her Instagram page next to an ultrasound photo.

Congrats to the happy couple! Watch the big reveal in the video below: