Maybe put it in a snake bag / pillow case and put it in your towel cupboard - just tie a good knot in the pillowcase so it can't get out as you can always cut into it to release the snake afterwards . If you have nowhere to hide the vivarium I'd put some plants in it temporary - house plants or a few out of the garden and tell him you are a plant geek and they need super-high humidity .. Or put the snake and viv / rub in the boot of your / friends / neighbours car with a hot water bottle under it for gentle heat .