Six Line and melanurus wrasse

So I was telling my LFS about my six-line Bering a complete jerk to any other fish I try to add to my tank as well as my issue with flatworms. He suggested adding a melanurus wrasse for the flatworms and said the the six line shouldn't really bother him. Well....

I added him to my tank and the six line has been chasing the melanurus relentlessly for about thirty minutes.

Will it eventually stop pestering him or is my melanurus pretty much dead? :(