Today's unsolicited dating advice for bros:
Always do this. Every time, even if it's early on and you're not sure what her reaction will be.
I have a bizarrely-clear memory seared into my brain of a moment when I was walking with a girl, thought about doing this, and decided not to out of fear/uncertainty over if she would react negatively. I regret it.
Just do it. Embrace your protector role, making it your default way of living. If she recoils, then that relays important information to you about her as well.
99% of hormonally-healthy, naturally-feminine women will take a BIG mental note of this as a green flag, especially if you just do it by instinct. Hesitancy/asking for permission is not what men do.
While boys get stuck doing mental gymnastics, men ACT. 
