She fully joined in!

March continued to rub both the guy's cock and the girl's pussy as they fucked in her Office.
As the girl came, she leaned back and kissed her boyfriend. March rubbed her to make sure she got the most of it...

She climbed off to recover and watched as her Instructor stripped off her boyfriend's remaining clothes.

"In a threesome, it is someone's job to clean up. It's not always the same person every time, alright.
You mind if I take my turn...with you?"
The girl nervously nods and says 'Go ahead.'

March happily leans in to suck the guy's cock, as his girlfriend joins in.
They trade off sucking his cock and balls.

After he's 'all clean,' March resumes the modified instructions.

"Guys love to watch girls have fun with each other. Kissing...touching...licking. Isn't that right?"
The girl looks at the boyfriend, who nods vehemently.
"It's not that he doesn't love you. He just wants you to be happy. Right?"
He nods again.
The girl smiles, fooled by this.
"So, as an incentivized lesson, I want you to lick my pussy...while he fucks you."

They both agree, with March in the middle of the bed with the girl facing her.
Her boyfriend is off to the side and moves in to fuck her.

"Some girls like being controlled, as long as it is by someone they trust. Let's see if you do."

March grabs the girl's head to focus her on the licking, while her boyfriend- per instruction- takes one of her hands and holds it against her ass while he fucks her.

The girl cums twice, while March cums once.
Newbies are energetic, but not precise.

"Very good. Now...may I fuck him, honey?"