Minor RI or Quirks?

[Bogertophis]

What you are likely hearing- since it's only when you handle him- is the "forced exhale" from the handling itself. Remember that our snake pals have a long lung (predominantly one & the other much smaller) that gets compressed sometimes just from our handling, when their body is "folded". That's normal, & IMO, it's more likely than your BP being suddenly annoyed by handling. I know it can sound strange & you're a good owner to be concerned enough to ask, but as long as that's all you're seeing, I think you can relax.

I used to hear it when I handled the large BCI I used to have, & one time when she was "meeting" some guys doing some work for me (who were admittedly uncomfortable about snakes), they thought for sure she was hissing when I held her. I had a little reassuring to do, & then they warmed up to her quite well, seeing how docile she truly was. When a heavy-bodied snake is over 7' long & you 'fold' their body, you're going to hear that exhale!