He's a tiny baby snake yet, & after only a WEEK you expect him to be OK with a giant (you're at least 100 times his size, yeah?) picking him up?
He's frightened & it's totally normal for baby kings to spray handlers with feces/musk as self-defense, because their mouth isn't big enough to bite effectively.
He's trying to make himself unappealing so that you don't eat him. I trust it's working?
Best results (for ALL snakes): don't handle until they've fed at least 3 times at normal intervals...NOT after you've only had him a week or so. Remember that
he was also at a show...very scary to a snake...and stress reduces the effectiveness of a snake's immune system. So if you want to chance making him sick with
any little thing he was exposed to (like at the show & before), then keep doing what you're doing. I recommend that you back off for a few weeks while he
settles in, grows a bit & de-stresses. You also mention doing this repeatedly for the past few days

...I repeat, leave him alone to settle in.
MBK's make great pets, but right now he's a tiny scared baby...he needs food & rest, NOT handling. Up to you to be patient...there is no rush to handle, he'll
still be tiny in a few weeks.