Cute alert of the the five-alarm sort! Justin Bieber's baby sister Jazmyn joined him onstage while in Argentina last week. So did his lil bro Jaxon... sort of.

The singer has caught plenty of heat while in South America -- the whole being filmed while sleeping thing. And when he was in Argentina, he was criticized for kicking a flag, thinking it was a shirt. He apologized profusely for the mistake, claiming he was unaware of what it was and that he was concerned about the safety on the stage, which is compromised by debris no matter what it's made of.

But something sweet and cute did happen while he was in the country.

He brought his adorbs little sis -- we love her bright purple tights, which are very in style right now, no matter what your age --onstage for her big moment in the clip above. We love her sass, too! As The Biebs high and low fives her, pulling his hand back, teasing her and leaving her hanging, she doesn't give up, even jumping to reach his hand. Jazzy's got spunk.

In the shaky, fan-filmed footage of 'Fall,' posted below, their little brother Jaxon is summoned to the stage. You might get sick watching it, since the filmer's hand is anything but steady.

The Biebs is seated on a stool, playing acoustic guitar when he motions Jaxon to come onto the stage with him at around the 1:30 mark. Jaxon was shy and wouldn't come to the stage! JB tried to drag his little brother into the spotlight, but he ran and hid. He wasn't ready for his closeup.

Jazzy didn't have the same fear of the stage! The footage below is the same as the footage above, except in longer form. It's also a little further back, so you're welcome for providing two vantage points.

Watch Justin Bieber Onstage With Jazmyn + Jaxon