Tl;dr I was in a relationship with a guy who was crazy emotionally abusive, forced monogamy upon me, and then cheated on me and was just all around awful. Our relationship died like a burning airplane full of dirty bird cages and hair, hurling into the ocean. Basically, I was not in a good place, emotionally.
So I used to work with a guy, Alex, who I had a bit of sexual tension with. We both knew we had this baggage with us – my terrible relationship and then the dramatic ending, and him with his… well, not terrible relationship. So it was one of those unspoken things where like we both knew we would fuck each other if circumstances were different but didn’t escalate it beyond being flirty with each other at work because it could just be so messy.