laurieaw wrote:
i noticed your BF was riding him with a nice, loose rein. is there any chance that you are using too much rein? i tend to do that when i get nervous, and when i finally get my horse going, he thinks i am stopping him. i am having to learn that leap of faith that he won't take off if i ask for the canter on a looser rein. and the last couple times it really worked.
This would be my first suspicion, too - the horse seemed pretty relaxed in the lope and went nice and brisk in the trot. When I was first working with my mare with a Western trainer, and had to ride her on a loose rein, it was a bit unnerving, but I had no shame about holding onto the saddle with one hand to help me relax until I got used to it. If you aren't already doing that, try it. For that matter, try imitating the slightly floppy body your bf is using - it may be floppy, but he's super relaxed. If you are a bit tense the horse might be feeling that and slowing down. If you exaggerate being relaxed by being floppy, you can experiment and see if that makes a difference.

Be brave, show us you riding him!