My 6-year old stallion started developing this habit of refusing to be mounted. He attempts to kick when his dressage trainer attempts to mount him, the trainer isn't someone who uses aggression, and is very patient, so I don't understand why he refuses to be ridden.
Once finally mounted, he behaves well, but the main problem is mounting -- this habit started about a month ago.
Any idea what could be the reason? And more importantly, how to overcome it?