Like you I was worried about the fact that my spouse has overstayed his B2 for almost 5 years. Last thing you want to do is to lie about it. Disclose that he is B2 overstay and give your address, assuming you live together. This issue was never raised before or during my interview. Just be truthful about everything and stop worrying. USCIS does not take it against you if you are married to an overstay. I became a naturalized USC last week and today we mailed my spouse's adjustment of status. Good luck to you.