I own a house and land. My fiance has no assets. Should I get a prenup to protect my assets?

I have lived in my house for the past !o years and have 4 acres of land with it. My fiance has no assets at all. Wisconsin is a community state proprty so if a divorce happened would he get half of my real estate even if I have had it for 10 years without being married to him. Would you suggest a prenuptial agreement? I also have a large retirement account and he just started his.