The past 2 weekends I've met women that have been receptive to me. They spend 20-30 minutes chatting with me, laughing, and being flirtatious. I'm good at reading women and they have both appeared to be into me. However, each has ended in me finding out they currently have a significant other. It's a total waste of my time. How can I find out more quickly if they have a significant other, in a classy way, that doesn't make me appear needy?