I know the whole thing is unlikely but who cares?
Disclaimer: I own nothing apart from the idea... :D

Sat in detention with Professor Snape, Hermione saw a large lump under his cloak.
"What are you staring at, Granger?" Snape bellowed across the classroom, Hermione turned away and went back to cleaning out the potions cabinet.
Awhile later and Hermione had nearly finished when she heard a muffled noise; she looked out of the corner of her eye and saw Snape stroking something under his cloak. She giggled at the mental image that was now running through her head. Professor Snape heard her giggle and quickly placed his hand back on the desk, Hermione noticed his hand was covered in shiny, clear stuff.
When she had finally finished, Hermione walked over to Snape and sat down on one of the desks.
"You can go now." Snape said waving his hand around in the air. Just as Hermione was walking out into the corridor she heard the muffled noise again, this time when she looked around she saw the normally horrible potions teacher stroking a ginger cat.
"Don't worry, Lily, she's gone now." Snape was cooing at the cat. A smile appeared on Hermione's face as she watched him playing with the ginger cat he called Lily.

Not what you thought it would be was it?