I am a divorced male living in NJ. I currently pay alimony and child support to my ex wife. I met a nice woman, a widow, and we've been dating more than a year. I rent a small apartment and she has a house. We are starting to talk about me moving in with her. I plan to contribute my share of the expenses but I think I need to make certain that what I pay in my new living arrangement is equal to what I currently pay out in my apartment rental otherwise I fear that my ex-wife will seek an alimony increase. Do I need a cohabitation agreement to detail what I pay if I move in with my girlfriend to prevent my ex-wife from gaining more alimony? Should I write my girlfriend a check each month or would she have to then declare that as income? I'm not certain how to move forward.