Look, just you've every right to be upset if it's Weasel and not you. But they had to have picked Bundy, right? I mean, she's utterly boring but she's also tops in everything, shockingly. And they can't have two halfbloods in the same house, so it would have to be Weasley, then. I'm sure it's not because of what happened last year and if you don't bring that up, then there's a much better chance everyone will forget about it.

As long as Mr Rosier's happy with your marks, that's all you really need to worry about. He knows that not everyone can be a Prefect--and anyway, you can still show leadership even if you don't have the badge.