"Robin! I demand that you stop this audacity at once!" the valiant Tamaranian yelled, on dangerous grounds; in between the punching bag and the Robin.
You see, reader, like water is blue and grass is green, a stressed Robin is a dangerous Robin.
Frankly, the other teenagers just didn't possess the patience, others, the attention span, to further deter this spikey and hard headed hooligan from continuing his endless hours of extraneous training and killing himself in the process.

But she continues to pursue her objective.
Her eyebrows are furrowed, an indication, and a warning that her schedule is completely and utterly cleared.
"Star.
If. You. Don't. Move. I. Will. Punch. You. In. The. Face." The words barely made it through his teeth.
One of her eyebrows rose, and then returned to its original spot on her forehead. She crossed her arms, a cocky smirk on her face.
She was stinkin' testing him.
He threw his hands up in the air with a loud and aggressive groan.
"You know, that's cool, I needed to move on to the treadmill anyway." He bluffed, hoping she'd leave.
He eyed her bitterly; with enough rage to transmit all the way to Raven's room and unleash the demon inside her.

She still stood in front of the punching bag, and he still stood in front of her.
Her smile grew bigger, completely inappropriate and irrelevant to his predicament.
What the heck.
"Do carry on, Robin. I remember I also have business awaiting me, I shall leave you to continue your… affairs."
Finally.
He knew she'd get tired of it eventually.
She made her way to the door, allowing him to resume his abuse on the poor bag.
"… I wish not to be late for my Portuguese lessons."

That was an obnoxious waste of time. He thought to himself.
Star was the biggest headache out of the others. It wasn't something he often admitted, but it was true. He allowed that to fuel him for the next couple of punches.
And when the heck did she start taking Portuguese lessons anyway?

….Oh for the love of Gotham city.

In total, it only took him 13 seconds to recall her previous experience of Japanese lessons in Tokyo.
And once he did, he dashed out of the gym to kindly provide his own services of English lessons…

Author's note:
Haha, notice how Starfire chooses her words very carefully….she would leave him to his affairs
Oh,
that Star.

By the way, Robin only offers private lessons.