Helping out a teacher before a lecture

You heard moaning left and right, as you went down the school's hallway. Students fucked in the most varying position some probably not even in the Kamasutra. The sweet and salty scent of sperm and cervical fluid was in the air and went up your nose stimulating your brain. It reminded you nostalgically of the wonderful times you had, doing the same thing all the "kids" around you were doing.
You stopped for a moment to watch a nerdy-looking boy ramming his three inches long penis into a blonde cheerleader girl, laying on the ground, whilst having her hands and feet tied together.
There is no hope for these children, you thought while going further. This boy's dick was way too small to ever please a woman properly.

"There you are. What took you so long? You know I can't start my lecture without a good fuck." Professor Lechner said while standing at the door to his classroom. He was a fat man with a bald head. He has a five inches long circumcised dick and a birthmark on the inside of his left leg.

You hated fucking him, but doing it is your job. You would prefer to suck on a big black cock, like Max's one. You started drooling just thinking about him, his chocolate brown skin, his defined muscles, and his handsome face. You felt fluid running down your leg.

"Hurry up already. Get in here and start sucking, There are only ten minutes before I have to start teaching again."
You got on your knees and helped the old man open his belt and pull down his pants.
You ran your hand along his leg, before setting your lips. Your tongue played with his cocks tip. Your hand grabbed Professor Lechner's balls. Your index finger and thumb twirled with the old man's pubic hair. You thought doing it was disgusting, but you knew this old geezer had a fetish for it.

You sucked as hard as you could, as fast as you could, to make him cum. Until he did.

You took his penis out of your mouth. You didn't swallow his cum. You thought it tasted disgusting, instead, you spat it into a sink next to the classroom door.
"It's disrespectful to spit out someone's cum. Next time you better swallow it."
As the old man put on his clothes again he watched you wash out your mouth. You felt his eyes on your body. Normally you wouldn't complain if someone would stare at your sexy body, undressing you in their mind, boy or girl, you would take both, but not this man. You hated it.

"Hey Alex, maybe you can swallow my cum later this day, my workday ends in about two hours and my wife is out of town this week. You could make up for the cum you just wasted."

You wanted to say no, but using your brain orderly for the first time in a while, you came up with a devilish plan to mess with the old man.
"Sure, but I got things to do for later, how about tonight? just meet me at the shabby mall south town after midnight." You winked at him to assure him for it was to be a date. A grin appeared invisible on your face.
You already planned how to mess with him, taking **** for all the times he used to exploit the services you offered the school.
"Sure", the old man said, flickers of joy sparked in his eyes. You knew from rumors running through the school, that between him and his wife nothing happened for years in bed and that he abused everything he could from the sex-hungry students at school for good grades. As
you left the classroom you heard his cheers of joy for finally being fucked. This man was pathetic.