have a thing about
Be obsessed or preoccupied with something. For example, He has a thing about disorder in the garage, or Bob has a thing about brunettes. [Slang; first half of 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.