As others have said, don't go on holiday with this creep. Why should you be stressed out and creeped out on your precious leisure time?
Second, if you do have to interact with him for any reason, I would completely ignore his weirdness and respond as though he had spoken in the most reasonable manner possible. He hasn't shown any sign of violent behavious (it would be pretty hard to deny and redirect, according to his M.O.) and he gets off on creeping you out. Every time you react or leave his presence to avoid him, he is mentally scoring a point for himself. So, deny him that satisfaction.
"Hoooow was the vacation, Suuuusaannn?" "Quite good, despite those two incidents." (look at him dead in the eye)
"Ooooh, you are aaannggryy." "No, why would you say that?"
Etc, etc, etc.
As to your husband. If he doesn't believe on this, you need a serious talk. Major serious talk. Ask him to leave you with the creep but, instead of going to the bathroom or whatever, to stand just outside the door so he can hear what is going on.