Well, Let me tell you a story. First, it worked well......Even if only to let me know the woman wasn't interested in being poly.
The story: I used to own my own martial arts school. Toward the time of my closing it, I had a student who had been training with me for 3 years. She is not a blackbelt yet, but is still training under my instruction. Well, I started flirting with her one night while she was working out on the weight equipment. (I also helped her with her weight training in addition to her martial arts) Anyway, I was over the top, and she was flirting right back....Sooo...I told her about "my friends". Her response? "Huh. Well, thats not for me at all. I can barely handle ONE man. Let alone TWO."
So it was not to be for me. I kept flirting, but I did so with a different mindset. Now, I know it'll never happen with her, but hey....at least I know.