The priestess gasped, obviously afraid of what the succubus was intending to do with that tail of hers.  She quickly tried to pleasure the woman, doing everything she could think of.  She plunged her tongue into the demon's slit, licking up and down, even sucking on it... though it was clear that not only was she completely inexperienced, she had likely never even experimented on herself, leaving her with absolutely no knowledge of what would feel pleasurable.