What are you guys talking about when you mean you are anxious about “opening up” to a woman?

I (22m) gotta know what it is you could say to a woman that would make her think you less of a man? I don’t doubt that it happens and that sometimes women didn’t actually want to hear what they were asking to, but what did you guys say to make them go, “Ope, this guy is obviously not masculine enough?” It’s making me wonder about my own support system. My parents, siblings, friends are all willing to listen to me talk about the stresses in my life and vent my real feelings and frustrations. Do I just have it too easy right now, or am I graced with people that aren’t the worst?