Threeway with a hint of jealousy (f/m/f)

I don’t really know if I would consider this a true threesome based on the events that occurred. But there were 3 of us, naked!

This all began with my old pal Nathan, and the new girl Bre. See my previous post for the deal on them.
A couple of months had passed since that encounter, and I left that night with confusing feelings. I hadn’t heard from Nathan and I blocked him on social media. But a few weeks ago he texted me, and we made small talk. He said he is still seeing Bre, but it was purely sexual. All they do is have sex, no dates, no meals, etc. He said he wanted to see me, and her, again at the same time. He said he wouldn’t be so focused on her and I would be in on the fun. I finally agreed, since Nathan does amazing things to my nipples. I also told him about my cuckquean fetish, which in hindsight I probably shouldn’t have.

Nathan and the other woman [f/m/f]

Years ago I dated a young man named Nathan. He was sexy in his own way. We did not work out in the long run, but the stories I have about him leave me breathless.

Nathan taught music on the side, he was a tutor to his peers. At this point in our life, we had drifted apart and were no longer in a relationship, but we would still hang out and have sex. One of the things we discussed was a threesome, but it never happened. I am afraid I would the jealous type.

So one day he hits me up, tells me to meet him after the last concert series of the year. So I slip in the audience to wait for him, since I was 20 minutes early. One of the last performers was named Breanne. This woman was beautiful and she could sing!! This must have been the Bre he mentioned a few times when we were dating. She was a short, brunette with bigger than normal size C breasts, for a small framed woman. She sang some song from a musical, I don't recall which. But towards the end of her song, her nipples became prominently erect. It must have been cold on stage, since her nipples were showing through her light pink cotton top. I was mesmerized. Song ended, Nathan and I met up for dinner, and we fucked after.