Partially

Your feminine moaning filled the room even more as Olivia said that, feeling the heat build inside of you, growing even faster whenever she spanked you, her hard thrusts shaking your body as you heard Stacey moaning too, no doubt enjoying the show of her roommate fucking you in this new, submissive and sexy form. You felt nothing but submission towards Olivia as she continued to fuck your ass, your moaning growing in volume until you finally felt it. The building pressure finally burst.

It felt better than anything you had felt before, your ass squeezing Olivia's cock and milking it as she continued to thrust, clearly about to cum herself. With a moan almost as loud as your own, Olivia finally came, and you felt her cock swell inside of you after one final thrust, before there was a massive eruption inside of you, your insides being coated by her warm cum. However, she didn't empty her entire load inside of your ass, instead pulling out and holding her dick so it would spray the reminder all over your back.

A part of you almost moaned from the sensation, and deep down you knew this meant Olivia had marked you as her property, something that, thanks to what she had written on you, you weren't too opposed to, if at all. A quick glance at Stacey proved she wasn't in much of a state to do anything, lost in her own world of masturbation, and under Olivia's control as much as you were now. Olivia herself seemed rather pleased with what went down, smirking at you, taking in the sight of your naked body covered in her cum. The look on her eyes made you shiver as she came closer, caressing your curves.

"You make such a good slut, Finn, Mistress is very pleased. But now Mistress' cock is dirty from cumming so much, and I want you to clean it", she said, and you were filled with the need to obey her, even if you knew exactly where that dick had been. Gulping, you got on all fours again and slowly approached her, your self-proclaimed 'Mistress' seemingly perfectly content with letting you do all the work.