Idiom
have a thing about someonehave a thing about (something/someone)
1.
to like something or someone very much or to be very interested in them.
I've got a thing about jackets - I must have twenty or so in my wardrobe.He's got a thing about blondes.
2.
to hate something or someone, or to be frightened of them.
Andrew's got a thing about children's TV presenters - he absolutely can't stand them.