Rocky slowly becomes obsessed with Grace’s ass. Like obviously he sees everything already, but there is a difference when Grace wears different things like thick material vs thin, and then nothing at all.
Rocky is initially intrigued by the sound of the weight there on Grace’s body. It’s a lot more than anywhere else on him.
Diagnosis? Grace has a fat ass.
In the moments Grace wears different types of clothing, Rocky gets better or worse looks at it. Rocky is pretty good at keeping his interest to himself though, until one day.
The day Grace forgets his clothes when he went to shower and so he has to walk back in nothing but a thin towel.
Rocky drops the tools he’s holding. He can literally hear the jiggle of it with every step Grace takes, and Rocky can’t help it. He acts on instinct as Grace passes him.
Everyone freezes. Rocky’s rebooting, both from his actions and all the new information he just received. Grace? He’s 100% sure he’s never made that sound in his life. He practically squealed, out of surprise and arousal.
The stinging/burning sensation still radiating through his cheek is filling his cock with blood. Rocky can hear that too.
That’s how Grace ends up bent over the lab table, towel around his ankles and Rocky behind him. Rocky squeezing and kneading his cheeks, spreading them apart. It’s so fucking hot to Grace. It’s the worst kinda teasing, and a little demeaning. Being played with and looked at so intensely.
He answers every question Rocky has.
“You like when hit. Question?”
Grace groans and hides his face in embarrassment, but nods desperately, his hard cock swinging between his spread legs. “Y…yes.”
Rocky proceeds to spank Grace. His cheeks red and prints of Rocky’s hand there, and that alone gets Grace so close. Rocky barely touches his cock before he’s coming onto the lab floor.
They’re holding each other afterwards, catching their breath, when Rocky speaks. “Play with hole next time? Question.”