What is up with my tang?

[hot reels]

I have a yellow tang who is in love with my large wild caught hermit crab (who is as big as the tang). Every night the hermit crab paces back and forth in the front of the tank, and the tang matches him step for step, sometimes in front (swimming backwards), sometimes riding on top (literally being pushed), and sometimes following behind, all the while frequently touching the crab. I don't see any signs of parasites or ick. Any clue what it fish is doing? At first we thought the crab would catch and eat him, but this has been going on for months.
Thanks
Sky

 

[carey]

I have a huge hermit crab, about 4-5 inches and just recently my blue tang has been snuggling with it. lol It's hilarious to watch but it doesnt seem to any harm so I've let it be. I thought it was just my tang lol

 

[Tkey3425]

Might be mistaking it for a cleaner and be trying to get it to clean the tang