You make Johanna tip you with her arse

"Take off your jumper and then mount me so I can fuck you in the arse," you instruct the unfortunate lesbian.

"Yes, Professor," she replies, successfully masking any hint of distress at her coming fate. She tries to get off the table and immediately stifles a scream as her burning bottom rubs on the tabletop. You help her out, putting your hands under her armpits and lifting her up in one motion, setting her safely on the ground. She thanks you and pulls her top over her head to reveal a tight, toned abdomen and a pair of very pretty little titties. While she neatly stacks her clothes on the table and smooths her long hair back into place, you wonder briefly whether her blush earlier was in part due to being so much less well endowed than her colleague, then your lust drives all other thoughts from your head, so you drop your trousers and sit in your chair, your prick jutting upwards obscenely.

"May I use some lubrication, please sir?" the Asian youngster asks, eyeing your bobbing member with trepidation.

"You may deep throat me briefly, if you wish," you reply as you sit back down in your chair.

"Thank-you, Professor," she says with apparently sincere gratitude, kneeling gracefully at your feet. The nineteen year old cutie opens her mouth as wide as she can and sticks out her tongue to guide your cock head inside, immediately closing her lips tight around your clammy shaft and starting to suck. She slides up and down a couple of times, her cheeks hollowing, then pushes forwards, trying to take you right down her gullet. She gags and retches slightly when you hit the back of her throat, but she forces herself to continue, swallowing repeatedly in an effort to progress. Realizing that she seems to be having trouble, you decide to help her out and put your hand on the back of her head. It only takes a small amount of pressure to finish the job and soon her lips are secure around the base of your prick.

You keep your hand in place, not holding her down by ****, but letting her know that you want her to remain with her nose pressed into your pubic hair a little longer, savouring her increasingly **** heaving and gagging. She resolutely stays down, struggling against every reflex of her own body to comply with your demands, until you release her and she rears back with relief, your dick, now slick with her spit, popping out of her throat with a string of spittle running from the tip to her tongue. She gasps for breath and then repeats her earlier words:

"Thank-you, Professor."

Standing stiffly, she straddles you, looking down between her legs to ensure that your manhood is lined up correctly as she waddles uncomfortably into place. She gently guides your rampant prick between her welted cheeks with one hand and lowers herself, engulfing your cock head and continuing down until her battered behind comes to rest in your lap. From the smoothness of your entry, you're sure she must be fairly well lubricated inside even beyond the spit she just deposited upon your cock—a sensible precaution, given the tipping rules—but this does little to assuage the agony in her bum hole from your pinpoint application of the wand earlier.

Johanna puts her hands on your shoulders for support and starts to rise and fall, squeezing your prick with her rectal muscles. You can see the strain on her inner thighs as she lifts and lowers her body, slowly at first and then gaining speed, looking into your eyes in an attempt to gauge your response.

As she gasps and whimpers, bobbing up and down on your pulsating member, your passion rises, increasing in intensity. Grunting in lust, you grab her hips and slam the small girl down on your prick over and over. Finally, she manages to bring you to fulfilment and a wide smile of relief covers her face as you fill her rectum with your spunk. She doesn't rest however, continuing to squeeze your manhood with her plundered arsehole until she has milked out every drop.

Although her performance was not entirely flawless, you can't deny that it was truly great sex, especially considering your student's sexual orientation.