As I said.. every time you go out to spend time with the horses have a PURPOSE. Do not just "hang out" with them.
Make a plan even if it is just to brush one or the other horse.
You do not want to be a member of their herd. Be clear and consistent with everything you do and have a purpose.
Some folks think they can "bond" with a horse like a herd member. You don't want to do that as a human. You want to be the human and be in charge.
This does not mean you can't pet your horse as part of something else you are doing (we like to pet horses!). It means have a purpose first and foremost and then add in the more fun stuff. Just be CLEAR and CONSISTENT and CALM and CONFIDENT.
I have been thinking about this, and I slightly disagree.
Yes, you don't want to just be a subordinate member of the herd. But, hanging out with the horses is not a bad thing, in my experience. you can just hand with them peacefully, AND, you can go up and move them around a bit, THEN hang out with them peacefully.
And as for petting, most horses don't really get off on being petted. they may enjoy a good scratch to an itchy place, and that can be a kind of pleasurable thing to share with them, as long as you can move them away/around as YOU direct first.
But, the thing that is the most rewarding for most horses is to be left in peace. of course, YOU don't get the 'credit' for leaving them in peace if you never work with or hang out with them. So, first you make them do something, and then you reward them by leaving them in peace for a bit, which feels good to them. you move them around, make them pay attention and move away from some food, or move away from you, or back up, and when they've done well, you turn part way away from them, and allow them to just stand there and soak up the peace of doing nothing. They perceive it as you just gave them some peace, so they credit you with both being able to move them around, but then also turning off the pressure and giving them what they love the most; peace.
So, just hanging out with the horses can be productive and pleasurable, to both horse and human. But I agree that having a "plan and a purpose" to how you interact with them is very good.