So, as it turned out, Karen was the first one to get Michelle involved in her fetishes and it was easier than I, Rhonda or Karen thought it would be. Rhonda was the oldest of the ladies at 35 years old. Karen was 28 and Michelle was 30. After several months of Rhonda, Karen and I fucking and the two ladies having their pussies stretched so much that they both permanently gaped, Karen started using Michelle's size 6 work flats on her pussy. Rhonda and Karen were both using Michelle's work flats as dildos and I continued to cum inside them whenever I had the chance. Michelle's work flats were beginning to look completely trashed but she continued to wear them daily. Michelle had to have noticed how trashed her flats were becoming but it became apparent she was liking that her flats smelled completely of pussy and were caked with dried cum inside.
I worked with Michelle on Wednesday and she was dangling and dipping her flats on and off her nylon covered feet. I had a monster erection and was doing absolutely nothing to hide it from her. Normally Michelle would sneak glances of the bulge in my pants but this time something different and exciting happened. I was standing near her as she sat down on her stool when she removed one of her trashed flats and put it right up to my nose. She asked me if they smelled worse than when she asked me a few months ago. My cock was throbbing in my pants and she put her other hand right on my bulge as she held her shoe to my face. She said she'd take that as my answer. I apologized but she assured me that no apology was necessary. She asked me if I knew if Karen was using her shoes to masturbate with. I quickly came up with a plan to get things rolling with Michelle. I told Michelle that I didn't know who it was but that she should ask Karen directly. Michelle said she couldn't do that. I told her I had a plan to help her find out. Knowing already that Karen did, indeed, want to fuck Michelle, I put her up to something to find out Michelle's reaction.
Karen was working the following evening, so I stopped by around supper time and asked her if she would push one of Michelle's trashed work flats into her pussy as she finished her shift. Her, Rhonda and I were planning on meeting at Rhonda's house after Karen got off work and I told her I wanted her to describe how Michelle's shoe felt inside her pussy as she worked. There were no customers in the store, so Karen grabbed one of Michelle's flats, hiked up her skirt and slid the dirty flat deep into her gaping pussy. I was so turned on watching Karen's pussy hungrily accept Michelle's shoe deep. Karen then dropped her skirt back down and resumed chatting with me. I left and headed over to Rhonda's to fuck her and fill her in on what I was up to.