It was also impolite to continue to press a point after assurance had been given. "Then thank you for being so reasonable." He was far nice than many she dealt with. Although he was, like her, more studious, so perhaps that was why.
"You have her in her favorite class. You can get entire sentences. I've known her since before we could walk, and she is good at putting up with me. Of course I've also learned how to read what she isn't saying. Me... I talk when there is something to talk about or someone interesting to talk to. When appropriate for an educated young lady to speak." Speaking to a professor therefore was appropriate.
However, his offer and smirk made her smile. "I know you are busy... And I've interrupted your work. You are in no way obligated to entertain me. You can tell me to go on my way... After all you are, as you say, far more mature."