Single guys: Do you have a female friend that you lean on as you might a girlfriend or wife?

I’ve always had far more male friends than female friends over the years, and I notice a pattern with my single (hetero) guy friends. They always seem to come with their emotional woes, their frustrations over being single, and usually a handful of flirty come-ons.
It has happened often enough that I refer to it (in my head) as being the “substitute girlfriend.”
Guys, do you have a female friend that you find yourself leaning on emotionally or flirting with, when you’re single, even if you have no intention (or perhaps option) of ever dating her?
Ladies, do you have a similar experience?

Just to be clear, I’m not complaining. I love my friends, and I think those that I have in mind are great guys who deserve to find someone that they love… it’s just an interesting phenomenon to me. I wonder if anyone else has noticed something similar.

And please, if you have a story that turns the tables, feel free to share that as well.