personally, i let my Male hang out on my neck everyday.
he likes it, i dont mind, he is the most docile pet i have ever had, and he loves to be taken out and held.

the only fear i have is that if he ever had the power to cut blood-flow(which i highly doubt) i would be afraid to hurt him to get him off me, i have no fear he can harm me at all.
call me ignorant if you wish, but i just dont see it as a possibility.

we both like him on my neck, sometimes he wont move for 15 mins or so.
would i try this with a larger snake? no but a 4' ball that weighs a few pounds, why not, he even gives me kisses