The pistons were activated!

Suddenly the piston gave another lurch behind you and the pressure built!

"Ummmmmmph"

Your pussy lips strained and strained under the **** of the phallus, but your tight hole would not give! The pressure continued despite the sexual juices pooling from your vibrating cunt!

"Aaaaaaaargh!"

Tears strained from your clenched eyes. You leaned into your elbows further and your little hands gripped tightly against the side of the mount in front of you. The pressure was unbearable!

"Come on, girl!" Professor Jennifer's voice came from somewhere behind you, "Remember to relax. You are going to tear your pussy before Master even get's a shot at you!"

You feel an encouraging pat on one of your ass cheeks behind you. You focus inward again and resist the animalistic sensation to fight the intrusion. Instead, you imagine yourself as a flower opening under the rays of the sun. Please... Please... Please...

Phuuuuuump!

The piston behind you makes a loud hydraulic sound as the resistance at your opening is overcome. The shaft fills the first few inches of your passageway in a forceful pop!

"Uuuuuurgh!"

The girth is almost unbearable! Your hairless pussy lips and the internal walls of your womanhood strained beyond reckoning. Slowly the piston **** the massive dildo within you. Your eyes rolled into the back of your head and a croak comes from deep within you. It feels as if your organs are moving around to accommodate, but even in your almost delirious state you know that is not true. Millions of years of evolution and a few deliberate surgical alterations had built you to accept this intrusion.

"Uuuuuuuurgh!"

The shaft continued its upward journey stretching your muscles tightly around its girth. The hydraulics pushed the dildo until it had hit your cervix at the entrance to your womb! Oh, gods! You remember thinking. It had felt like you were being punched within your guts! The pain was excruciating and the shaft would only have been half in! Your body had begun to cramp!

"Remember to adjust your position, Areli!" Professor Jennifer shouted down at you.

You rocked your hips and back until you found a more acceptable position. You tried to concentrate on the vibrations in your clitoris. Somewhere beneath the pain... another orgasm was building inside you.

"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah!"

The orgasm was loud and violent. Your strained muscles clamped painfully around the shaft buried within you and you felt it begin to move further within you. You bit your lip and tried to hold the correct angle that allowed the dildo deeper inside of you. The head was now missing your cervix and the pain diminished slightly. You opened your unfocused eyes and began practicing your breathing exercises.

"Heh... heh... heh... heh... uuuuuuuuuuuuuuuuugh!"

Additional orgasms took you as you felt the base of the dildo slap against your pussy lips. You had successfully accepted all 10 inches within you! You had tugged against the leash around your neck and threw your face skyward with another orgasmic moan. You remember feeling a smile cross your face. It was hard not to be amazed at your own skill!

You and the other girls had been **** to endure the full penetration for another fifteen minutes. Each of you spent that time with your engorged clits buzzing and pussies cumming around the shafts speared deep within your forms. You do not remember the shaft being removed. You had been too delirious due to the painfully pleasurable intensity!

You had passed Breeding 101! You could now be bred by Master!