I feel horrible saying this. But I have gone the parents route. I wanted his mom to know my aside. In the majority of the cases, the parents will hear you but still side with their child. You keep stating that you do not want them to hate you. If your wife is a messed up as you say, they already know.
Why do I feel that your motives to talk to her parents are more of a reaction? Let her tell them. They know their daughter better than you think, and even then they completely understand, they will most likely back off from you.
