This must be a trick, Mimi thought. Draco must have been quite hurt by her actions that he thought the best form of revenge was getting close to her and betraying her in the end when she least expects it.
Mimi was not a kid, she had seen tricks like this all of the time. Back in high school, she had many admirers, and one of the boys she rejected his advances was a sore loser and tried to get back at her that way.
But Mimi stood her ground and learned from the others later that the boy had made a bet with his friends to make her fall for him. His plans failed obviously, Mimi was not gullible.
Hence she saw the same thing happening with Draco now. Feeling humiliated from their last encounter, he must have made a deal with his gang members to deceive her. Whatever evil plans he had in store, she was not going to be a victim of it.
