A few months ago at a bar I approached a guy and asked if I could sit down. He said point-blank: “I have a boyfriend but you wanna stay and chat?” I was like “yeah okay” and we talked for a bit and then his friend abruptly rushed up and exclaimed to him, dramatically and in earnest, “your boyfriend’s here!” I look and about ten feet behind him is a guy staring at me and approaching slowly. I calmly (but immediately) got up and walked back to my friends and took a seat with my back to the scene. My friend said that they kept looking over at me. In retrospect, I think that my wordlessly getting up and walking off may have actually worsened the optics of that tableau. Perhaps I should have stayed and introduced myself to the boyfriend, all sweetness and light.
At any rate, I found out that they’re not together anymore, so I shouldn’t have the same problem next time.