The Locker Room II: The Shower
First there was the hot tub, then the hand over the partition and then this.
Read Part I here:

I didn’t know what I was doing—why I’d come back in, why I’d chosen that stall. I wasn’t hard. I wasn’t expecting anything. But I was keyed up, every nerve straining for sound. A footstep. A curtain ring sliding. The shift of weight just a few inches away. I was listening for him.
Then I saw it—his shadow on the tile beneath the partition. Still. Then shifting. Then that familiar motion: the slow, rhythmic movement of his arm. My breath caught. I didn’t need to see his face. I recognized the pace, the intent, the quiet confidence. He was jerking himself. And he wanted me to know it

