That's the white one with the black on the tip of it's tail, right?
It also followed my wife and I as I was drifting/hunting for lionfish. It would come within inches of me. I kept pointing at my sling and trying to point to the reef, like trying to get a hound to try and hunt. Didnt work. The great part to this story is I never saw one lionfish on the reef. That was cool, because months before there where lots. He followed us to the end of the reef and turned around. It was my wifes' fourth dive. It blew her away this fish the size of her was following us around. I had told her prior that the snappers did this, she wasnt quite ready for a 2 hundred pound fish to follow. lol. Next time I have him follow I will point the lionfish out to him and see if he will get it. Havent had the chance to try that yet.