Are prenups common for a lot of couples. Is it red flag if a man wants you to sign prenup before marriage? I agree that may be if you are marrying someone who is ultra high net worth person, you will need it to ensure proper allocation of money between the couple. But in other cases it sounds offending to me. If I am willing to leave my job and marry a man and even then if the man asks me for a prenup, it makes me feel that he cannot ever trust me.