I had a horse and with me he would go great. Moving forward immediately of aids, jumping, etc. He wasn't a beginners horse though, an ex racehorse who raced for a long time, he was smart, a little crazy at times, strong and he really had his moments but I loved the way he tested people. When people find out you have a horse they always want to ride and you can't really say no without being rude but even though he was not a beginners horse I always felt fine putting people on. See in my experience people always say that they can ride a horse but this horse was such a great test.
If someone who couldn't give strong clear aids, hold a good contact etc, he just wouldn't move. He was normally so sensitive to leg but a beginner could sit there and kick and wouldn't budge. Just stand there doing nothing. Maybe they could convince him to walk, at best a few strides of trot but that was only people who at least had some clue.
Was it good behaviour? Probably not, but he wasn't a beginners horse, he wouldn't be safe for beginners to ride outside of an arena. Its not something I could fix - I mean anyone with the skill to fix it would get on and he'd be an angel, but I didn't mind it. I think it was good, it stops a horse falling into wrong hands or getting someone in trouble. Horses test people for a reason I think, if you can't pass you shouldn't be riding that horse - you are simply not ready if you cannot enforce your aids.
Sorry, but your boyfriend sounds like a jerk. Tell him to keep to his horses and you can keep to yours. I wouldn't send a horse to a trainer because your boyfriend can't ride. I don't really think much of riders (at least the kind that talk themselves up) that cannot ride a range of horses.
Your horse works for you and that is all that matters.