Perhaps

He slaps her and it feels so good: that sense
Of power rising, as his hardness grows;
She kneels and knows it's time for recompense -
To serve her Master with her holes. She shows
No hesitation, as she opens wide;
The tenting cloth before her, as she slips
Her hand out to caress him - let's it slide
So gently up his thigh - then she unzips
Her heart's desire - she understands and serves
Herself with heady options; but she waits
For him to give permission as she curves
Her hand beneath his balls and, as she slakes
Her taste for cock and come, she thinks perhaps
If I perform quite well I'll earn more slaps.