Personally, I'm horrible when it comes to girls. For some reason I can't tell when a girl is flirting with me, even though I'm really interested. Example: girl walks up to me at the club, says hi, bends me over the bar, lifts up my dress and starts spanking me. She giggles, introduces herself, and then runs away. Apparently she was flirting with me, how I didn't get that then is beyond me.
The two times I've ever had a three-way, the girls faked interest in me just to get to the boy. Not cool at all. And that is probably why I have a hard time figuring out if girls are genuinely interested or not.
But I agree, let her find the girl.