How did you do that!? That's cute. My BP will come up to the glass when I stick my face up to his vive, but that's about it
OP definitely give it time. I had a very defensive corn (I know not as big as a BP but trust me, just as scary when you're new to snakes) who bit me literally a hundred times. Even as a yearling at 75grams she drew blood.
It WILL get better with handling! As long as you are patient yet persistent, and don't put them back when they are in a grump, it will work out for you I'm sure.
Best of luck!