At one of my previous jobs (before the internet era with Tinder, Match, etc.), there was an MILF admin who became a friend with benefits. She was a single mother and didn't have much time for dating. After we had hooked up a few times outside of work, some flirting started to take place during the office workday. To avoid any office issues, we found a quiet, little-used work area in our complex. As she managed my boss's calendar, it was easy for us to sneak away for an hour or so. The first few times, the fun was often me going down on her, pleasing her till my tongue and mouth brought her to an orgasm.

One time, after spending a couple of hours at her place, I left her a small remote vibrator with a note: "When you need 15 minutes, I hope you use it and think of me."

A couple of days later at work, she sent me the usual message to meet up at our hook-up place. After a kiss, she held up the vibrator and said, "What's this about?"

I replied, "Well, it's for fun at home. To help you sleep."

"Oh, this wasn't meant to be used during the day?" she asked.

"Well, of course you could, if you want," I said back.

Then she pulled out what I recognized as a butt plug. Very sternly, she said to me, "I'll use it at my desk and leave the remote on the side, but only if you use this plug."

She didn't know it, but I've had plugs, dildos, and men up my ass before. Feeling turned on, "Challenge accepted" was my response.

To make sure I had it in me, she was going to insert it right there. I dropped my pants and boxers, and after she spit a couple of times on the plug, she forced it right into me. I felt myself start to harden. She smiled. "Looks like you enjoy that, huh? Maybe something new I need to add when I come over next."

Then I said to her, "Now it's my turn." Instead of spitting on the vibrator, I went down on my knees and slid my tongue into her, spreading her labia. My nose rubbed against her clit. I slid my tongue deeper as I felt her get wetter. She placed her hand on my head and told me she wanted more. The feeling of her juices all over my mouth and chin made my cock harden. I stopped, took the vibrator, and slowly slid it into her. As she pulled her panties up, I turned the vibrator on from the remote, making her legs buckle. I turned it on again, making her squirm in place.

After we fixed our clothes, I awkwardly walked back to my desk while she easily strutted off with a smile on her face. As I sat in my chair, the feeling of that plug pushing up into me kept me hard. At my desk, I kept moving in my seat so that the plug would move about. My co-worker in the cube next to me must have heard me, because he asked if I was okay. I was feeling more than okay with my cock fully hard in my pants.

Seeing someone talking to my admin FWB, I walked over to her desk. I pretended to look for documents and saw the remote. I saw her eyes widen at me. Then I pressed the button to turn it on low; I heard her pause. The person talking to her asked if she was okay. She started to stutter and said something was stuck in her throat. I turned to her and gave her a wink, then turned it up. She started fake coughing and told the person she needed to go to the ladies' room to clear up. With the vibrator still on, I told them I'd better leave to not catch whatever she has.

As I got to my cube, I could hear her footsteps quickly approaching. She saw other people in their cubes as she chased after me. I stood at the entrance of my cube, and she whispered, "What the fuck? You can't do that with someone there. You can't just leave it on either." I smirked at her, then put her hand on my hard cock, which made her smile.

As she walked away, she shouted something work-related at me, trying to keep our FWB quiet.

The next time I went by her desk, I saw her looking at me with anticipation of whether I was going to turn it on, but I didn't, keeping her in suspense. With her back to the aisle and no one bothering her, I quietly sneaked up and turned on her vibrator. I saw her instantly grab her armrests and give out an "ohhh." She turned to face me and blushed. As I saw someone approaching, I turned it off with a wink and a smile.

After an hour or so of sitting during meetings, my ass had gotten used to the plug, and I only really noticed it when I got up and went around to my favorite admin. This time, she was on the phone and gave me the look of "Don't you dare." So, of course, I turned on the vibrator. I got excited seeing her blush and watched one hand cover her mouth as another grabbed her chair. Then someone called me over to their office.

About half an hour later, I sat at my desk working when she came by.

"Hey, where did you go?" she asked.

I started to give a work-related answer when she threw her panties in my face. I immediately felt the wetness in them.

"I need to pick up someone by the bus station on the way home." Code for she wanted to stop by my place. Then she whispered, "Tomorrow it's your turn to have this vibrator in you."