My black kingsnake never come out

[creed0513]

I got Black Kingsnake 3 weeks ago, i understood he needs time to get used to new place at first. However, it's been three weeks, and still he hides under aspen bedding and never come out when i am around. I can see him out when right get back home, but he hide back asap as i am near him. He is about 8 months old and about 18 inch length. I do handling him twice or three times a week, and he seems never gonna get used to my hands. Every time I try to give him handling, he shakes his tail, poops and makes bad scent. What should i do to make him more friendly?