Um... yeah, I just said I did.

Kathy slid her grey skirt down to her ankles and stepped out of them, leaving her outfit entirely consisting of a pair of purple and white striped 'boyshorts' style undies. I assumed this was what she would be wearing under her gym uniform, perhaps even plus the addition of a sports bra, but to my surprise she suddenly removed these too.

After placing all of her removed items into her locker, Kathy turned to me and explained.  

"My regular gym uniform is in the wash, so I grabbed my workout uniform instead. It's usually too revealing with the guys here, but I figured with most of them gone, and the rest--" She looked me up and down. "...in no state to complain about it, it shouldn't be a problem." 

Kathy took a pair of white ultra short boxing style shorts with a black waistband out of her gym bag, and sat her bare bottom down on the wooden bench. She slipped her feet into the remarkably small leg holes in the garment, and pulled them up her legs with some difficulty, due to their tightness.

I continued jerking off as I watched Kathy stand up and pull the tight shorts over her shapely butt. The idea that my masturbating to this scene was rendered devoid of significance by my medical situation was a strange one to me then, though later I would find it liberating. Kathy reached into her gym bag and dug around in it for a few seconds, perhaps looking for her top. 

"Aren't you supposed to be drinking lots of fluids?" she asked me, momentarily looking up from the bag.

"Oh, yeah," I responded. I slid the straps of the backpack which I still wore off of my bare shoulders, and put the bag on the floor. 

By the time I had gotten a bottle of water out and removed the cap, Kathy had apparently found her top and taken it out of the bag. As she slid it on over her head and upward-stretched arms, I could see that this white tank top was not made out of a solid material, but rather mesh, so that her nipples were clearly visible through the material. The bottom stopped a few inches above her navel. I watched as she glanced away for a moment and absent-mindedly yawned and rubbed at her breasts, more of a random gesture in this case than a sexual one, causing her nipples to become erect, and literally poke through holes in the mesh.