Working in veterinary medicine, one of the biggest things that bothers me is when an owner states that their animal is "naughty" or laughs it off when they bite, scratch, growl, generally act like a jackass, etc. The same is true for horses. Bad behavior in any animal companion is not funny, not cute, and not to be taken lightly. ESPECIALLY when the animal weighs half a ton and can crush you. That horse DOES NOT respect you, and that is sad. I find it to be a wonder that you are living to post these worrisome photos.
Besides that, I guess all I can say is... nice seat you have there.