When I was younger, I had several close male friends. As the years passed, that shifted as I realized either they were hoping to sleep with me by playing the friendship card, or as soon as they were in a committed relationship, it felt like "Neelou who?"
In my mid twenties, I stopped keeping the company of male friends (unless they were gay) ... with the exception of Gil, my best guy friend. Other than Gil, I firmly believe that there can be no true, lasting friendship between members of the opposite sex. Not a close friendship, at least. If you peel back enough layers between two friends of the opposite sex who spend a lot of time keeping one another’s company, one always has feelings for the other.
And then ... my hypothesis was proven, without a doubt.