Here's something Gus and George and Bridget have taught me: Broadside approaches are to be avoided.
I have remarked that Gus and George have a sense of vulnerability about being approached on their flank. Recently, when they were being especially nice to me, they each deliberately put me next to their flank. They did not achieve this position by sidepassing up to me, or pivoting toward me. Instead, they started with their head next to me, and moved forward, sliding against me until I was level with their flank.
When Bridget wants me to scratch her quarters, she doesn't just come up and swing her tail end into me. Again, she starts at her head or shoulder and rubs against me like a cat and then pushes her quarters against me.
I think to be in that potentially threatening position as a friend, you have to "enter the house by the front door." That is - you have to start at the head. George and Gus showed me the way to enter. On the other hand, I think Bridget, who is not nearly as picky as they are, slides against me for my benefit to show that it is not a hostile butt-slam which is coming up, but a friendly one.
Of course, that's how horses are mounted - from a broadside approach. And a horse in cross ties is constantly bombarded by humans coming up to him from the side.
Us humans are not very mannerly.