Two related anecdotes.
1. A woman who has recently moved to this city is walking down a residential street with me after dark. She is at the tail end of five minutes of stories relating surprise at the frequency and intensity of catcalling here relative to other places she has lived. We approach three 18-to-21 looking males hanging out on a street corner. They are obviously wasted. As we walk past, they say nothing to her but one nods toward me, makes eye contact, and gives me the trying to be cool "sup" that young males do.
2. A different woman is having dinner alone at a bar. She texts me to live blog the old creeper who is accosting her (not physically) and does not seem willing to leave her alone. She laments that she does not have a boyfriend or at least some male to sit next to so that she might go to a bar and sit there in peace.
It's equal parts intriguing and disturbing how often men treat women with respect – not invading their personal space or shouting things at them that they would prefer not to have shouted at them – not because they think women deserve to be treated with respect but because they are with a man. The inebriated young men didn't refrain from making suggestive comments because they realized that it's inappropriate; they refrained because I was next to her. Old creepers and "pickup artists" do not leave accompanied women alone at bars because they recognize that ignoring all the "please stop" signals is behavior that trends toward Rapey. They do it because the has a Sold tag on her and is already the property of some other man. And many men who would happily treat women with the utmost disrespect would recoil at the thought of disrespecting another man by hitting on his Property.
Many years ago I accompanied a female friend, at her request, to a car dealership. Being younger it didn't occur to me at the time that I wasn't there because I have any special automotive knowledge that might have been useful. I was there because if the (inevitably male) car salesman wouldn't treat her too insultingly in front of Her Man. Women are probably so familiar with and used to this dynamic that they barely bother to think about it anymore. I, on the other hand, never thought about it seriously until the two incidents above happened in quick succession. I understood intuitively for a long time that having a male companion helps women receive better treatment from other men in some circumstances. However, I only recently did the math – women only get treated respectfully incidentally, as a side effect of respecting another man's ownership.