Keep going

You decide you're too far into this to stop. Maybe it's to buy your friends more time, maybe it's the arousal running through your body, but you keep going.

"Bark! Bark louder!"

You continue barking at a louder and louder tone, watching her gasp and moan as your cock slams into her, your balls swinging through the air and slapping against her clit with every thrust. The wet squelching grows louder and louder as you continue to hammer into her. You give her ass a hard slap, watching her flab jiggle as you do. You grab the sides of her waist, using it to thrust deeper and deeper inside of her, jamming your cock as deep as you can into her.

"God dammit, you feel so good! You're the best puppy I've gotten to use yet, aren't you!? One of my favorites!"

You continue letting out loud barks, filling the air as you quickly bring her to another climax, your heavy balls getting ready to fire. The thought of spewing your cum into the pussy of your principal is definitely a turn on, and as her groans of pleasure quickly come closer and closer to orgasm, her heaving tits slamming against the table as you continue to fuck her, her pussy juices now coating your cock, balls, pubes and thighs. Giving one final slap, you penetrate deep inside of her, your balls tightening as you let forth a torrent of spunk, spraying it against the walls of her pussy and deep inside her womb, letting out one long bark as you do so.

"Jesus, that was good," you grunt.

"Yeah, you were really worth the money. Especially with that discount you promised, right?"

"Oh yeah, don't worry about that!"

"Good," the Principal smiles. "Alright, let me get some coffee. You head to my office, and get ready for round two."