First off all, I'd just like to say I have a horse who Does. Not. Bolt. Usually.
In the past that statement would have read Does. Not. Bolt. Fullstop, but today she defied expectations and years of experience and took off with my friends boyfriend.
So we all went on a trail ride, three horses and four teenagers. Three would ride, and one would mind the dogs. Friends Boyfriend (here on out referred to as FB) wanted a canter, so it was decided all the horses would canter up the hill. Black horse took off. FB suddenly chickened out and tried to keep trotting. Chestnut horse was slowed to a trot and did a very hasty trot for a few moments before the rider gave up and let her horse canter. Chestnut horse cantered a few strides but stayed beside my mare.
At this point my horse and FB were still trotting, when they trotted under a branch. FB leant forward and my horse took off. Apparently, according to several witnesses she actually galloped, pasted Chestnut and FB sat that gallop for a few moments before he tumbled to the ground. My horse stopped a few strides later and I mounted her.
She was slightly spooky but fine.
We recreated the event, with Black horse galloping for home right past my horse. My mare keep walking. Quietly. As she was trained to do. As she does every. Single. Trail ride. Ever. I even leant forward and wrapped my arms around her neck to see if she'd take advantage. Nothing.
Another friend also got on, and cantered my horse both away from (out of sight) and back towards the other riders. Still, her manners were fine.
I am slightly annoyed, not only because FB came off but also because she was naughty. And also because she was only naughty for him. Any ideas about why the sudden change of heart for a different rider? And how I can stop it happening again?