No Seperation

Currently I am not seperated or divorced. We have not lived together for over 2 years and I would like to get a patent on an idea I have. Is it smart to get one before any legal seperation papers are done?

It would be best to have a separation agreement executed or an equitable distribution court order entered, or an absolute divorce judgment entered, prior to obtaining a patent. If you were to earn money from the patent, you presumably would want to make sure that income is your separate property, which would be clarified in a separation agreement or equitable distribution court order, or by having an absolute divorce granted.