Justin Bieber, Selena Gomez lunch friends toddler Benihana
Justin Bieber, Selena Gomez lunch friends toddler Benihana

Justin Bieber, 17, and Selena Gomez, 19, were on babysitting duty Saturday, taking care of Biebs' half-brother Jaxson. And the two look pretty comfortable with childcare!

Bieber turns 18 in a few days, but even at such a young age, he was up for the task of taking the little tyke out to lunch. It was Benihana for the trio ... wonder if little Jax got the steak and shrimp or the chicken and shrimp?