It's an idiom. A similar idiom in English is "you would like that, wouldn't you?" The meaning is that the speaker thinks the listener is taking advantage of something for his own benefit, and points it out while disagreeing.

Actually not that easy to translate.... passen = fitting, to fit Das würde/könnte dir so passen - That would fit you However, it is mostly used in a negative context. Example: A: I will use the car today B: Das könnte dir so passen (means: I strongly disagree) (ich hoffe jemand anders kann es besser erklären)