Tracey shouldn't have agreed to dinner. She knew that. No matter what she'd told him before - something about strings - she knew it wasn't something she should pursue. She had plenty of other things to keep her occupied - plenty of other men to spend time with - so she was really in no need of a halfblood who was more muggle than wizard.
That didn't explain, however, why she was standing in front of his flat now and rapping impatiently at his door. She'd have to come up with a reason for it later.