Horse acts badly when ridden by others- only when I am there- how to stop?

My mare is very bonded to me. For an example, if I don't go out to see her enough, she gets aggressive and beats up other horses in her pasture, though she is normally docile. She used to get aggressive and attack people when I was gone for more than 4 days, but thankfully, she has gotten over that a couple years ago.

I am currently half leasing her to a classmate, and when I am not there, or not visible to her, she acts perfectly fine and behaves. If I am in the arena reading a test, standing there, or even if I was there and left, she acts up. It is nothing dangerous, but she will misbehave- start weaving around in her gaits, not listen as well, lose connectivity and rush through aids. My classmate really has to work to get her to look good after that, though normally has no problem. She does the same thing to my mother, and her instructor even commented on Chynna's change in behavior when I'm present.

I swear Chynna is trying to make others look like bad riders when I am there so I will ride her instead.

We normally don't go to the barn together, so it is fine, but we are both going to a dressage show in a month, and Chynna will know I am there.

Any suggestions on how to fix this? I don't want my classmate to have a bad ride at the show just because I am on the grounds.

Is this behavior set and nothing I can do about it? She has done it since I broke her to ride, and she is 10 now.

I should ask, how can others or them and me stop it, because if I get on her, she will quit immediately and be a doll.

Some horses are more reliant upon trust issues than others. For some reason it sounds like your horse feels insecure with others and that is manifested in her behavior. Horses like Chynna do best when they are handled and ridden by only one rider. Unless others who ride her can put in the time to earn her trust, there is possibly no other solution for this individual horse.

From just reading the title, your horse is a one person horse . Some horses don't like being ridden by dif. people, thats just that .

For the showing part, don't let her see you at all and don't go to the barn, take a dif. ride there with your mom & stay completely away from her & the rider until she is done .

Mares tend to be stubborn like that.
and if she has such a great bond with you, she just doesn't want to be ridden by anyone else. a lot of horses are like that.
all i can suggest is to keep working on it, practice makes perfect.

good luck

that's how they behave, the only thing you can do is to get a professional trainer for her, or just let it go and don't go into the arena when someone is riding her.

Wear sunglass's and a fake beard,or stop watching

Just trying to be funny! Sorry!!

Mares are just kind of stubborn like that!