First of all, if you remarry without a marriage certificate, there is no marriage relationship in law, just cohabitation. Now that you live with him but buy a house together, it can only be in the form of partnership. It is risky for you not to master the contract yourself: 1. Legally speaking, changing the contract requires the consent of all parties concerned, that is, you have to participate in it and reach an agreement with your "husband" and the seller (if there is a mortgage, you need to reach an agreement with the loan bank); 2. There are often irregularities in law enforcement in China. If your "husband" changes the contract after signing the contract instead of you, your rights protection will be very difficult. You need to produce a lot of evidence to prove that his signature is invalid without your authorization. It is also necessary to correct the bad consequences, sometimes it may be unsatisfactory for many years, and the cost is very high. So I suggest that if two people plan to live for a long time, they should go through the marriage formalities as soon as possible, and then buy the same property, which will be very easy to handle.