Pois are "typically" one person birds even when socialized from a young age. The genus just seems to be a bit more 'hardwired' toward this tendency than the South American species for example.
Pois in general also tend to be quick to get freaked out, or change moods within a second, quick to displacement bite... To an extent, I'd say get used to it lol! Those Pois bite hard, and Jardines beaks aren't small!
What do you or your bf do when he bites? Do you tell him no? I'm not an advocate of ignoring the bite or the redirecting method with Poicephalus. He needs to learn bite pressure training for sure. of course he will still bite hard at times even after he learns this, but IMO and IME it's imperative to teach a Poi bite pressure training at least so he knows what he's "supposed to or not supposed to" do.
Start by using a cue word. My word for Griffin is "gentle" with a finger right over his beak. Say it calmly and relaxed, he should over a little time, start to get what you mean. He now many times will loosen his bite and nibble, or not go in full force. Notice I said "many times" and not "all the time" lol. He IS a Poi

. At least he now knows what it means, and what makes him a good boy vs a bad boy.
A lot of the infamous Poi biting I truly believe, is more of an automatic 'knee-jerk' reaction that they just tend to have. Still, I wouldn't trade them for the world

. Also, make sure he sees your or your bf's intentions (what you're about to do with him) as to not startle him into bite reflex.
I know he's still new.. In time you and your bf will start seeing more of his personality, his likes and dislikes, etc. For now I'd be careful when either of you are handling him, especially bf. If he's getting overstimulated (watch eyes pinning, standing tall and raising out feathers, etc) he most likely will bite. Even if he's overstimulated from having fun. Another thing, Poicephalus don't always have a lot of overt body language before striking. They're a species (genus) that is not real obvious to read many times, which can lead to more bites. I love the Pois though. My favorites.