Jeff looked at the person he had hosed down moments before and recognised the goth girl he shared a few classes with. Jeff had not known the girl very well at all and this just added to his shame about the entire situation.
The girl was engolved with his fluids as the transformation took its effect. Her black boots ripped open giving way to her gradually enlarging feet who's nails had molten together into a single hoof and her face was pushing in forward into a small muzzle as she became bigger all over.
Once the shock had disensed the goth girl recovered her posture. She looked like she was going to berate Jeff for his shamefully lack of control before she closed her mouth turned around and walked away to clean herself in the woman's bathroom.
This was now officially the worst day in Jeff his life. He tried to stand up but quickly felt restrained by his clothing as his experience had gained him new bulk. He had to rip his shirt and resort to only wearing his slightly better fitting jacket in order to stand up.
Looking into the mirror he was able to fully see his changes. Besides his bulk he had been spared much more humiliation. Jeff was mostly mad. Mad at liz and the students that did this to him and mad at himself for causing this entire situation in the first place.
Then Jeff looked down at the jiz covered stall and water fountain and he made a decision. He was going to get revenge. Jeff grapped a plastic water bottle and filled it with his fluids. The cheerleaders and jocks had practice together today and always had shared drinks. A perfect spot for his personal ingredients.