Difference between Have a thing about someone and Have a thing with someone

have a thing about someone—(coll.)

1. feel a strong attraction to smb.:

• That smile, that jawline. No wonder Jacquie had a thing about him.

2. harbor a prejudice or fear about a person:

• Connie’s got a “thing” about police. “Never trust a policeman” is her motto.

have a thing with someone—(coll.) have a love affair with a person:

• “Are you sort of having a thing with Madalena?” “I’m interested in her,” he said. “But not sexually.”