Hmmm .. im no expert but i think the home change and new pet could triger the behaviour change. You will need to let him get used to the new environment so leave him alone for a week or two.

Snakes can detect even the slightest change of air or environment so im guessing they can sense the kittens odour. Again, just let him get accustomed to the new surrounding and its best you wash your hands before handling your snake. I have a cat at home and my bps are used to it, I think they can tell the difference between my cat and food. I dont however let em get close to each other and i still wash my hands before and after i handle my snakes.