There was a time in my life when all of my friends were guys. We all drifted apart over the years but I still keep in touch with a few of them now and then. I was the token girl of the group.
I have met a few guys that turned out to be wolves in sheep's clothing, but I have met girls who turned out to be wolves in sheep's clothing too.
Now my best friend is a guy.
I have always acted like myself in these friendships. I can always talk about adult things with them because I wouldn't befriend anyone I couldn't talk about adult things with. In fact that was one of the reasons I started gravitating towards guys in the first place. I could tell them about my sex life without feeling judged, as girls tend to be prudes. Sometimes it's platonic, sometimes it's friends with benefits, sometimes it leads to a relationship, but I always just go with the flow.
Someone said a guy-centered friendship is talking about chicks/lifting and a girl-centered friendship is talking about an emotional breakup with an ex??
My male friends and I talk about politics, religion, philosophy, dating, careers, sports, sex, music, exchange advice... they're human!
What's the point of making a true friend if you can't be true around them? By the way I have never befriended an effeminate male.
Always be yourself. Don't become a slave to rules. If you want to know what is going wrong or if you're sending out the wrong signals, just ask him!