If the two are linked, it will be easy. Now it's separated. It's a little complicated.
First of all, taking pre-marital property as mortgage loan after marriage can be regarded as personal debt, but the marital loan bank has its own requirements, that is, both husband and wife share the responsibility. If they are single, ask them to issue a single certificate. In this case, after signing the contract, if your husband and wife have no objection, * * * will bear the bank loan debt and register the house in his parents' name. There are two possibilities. The first one is regarded as his personal debt and his personal gift to his parents (real estate). The debt you bear with him is actually that you help him bear the repayment. If you divorce, you should compensate for the contribution you made with him. But in marriage, it should be regarded as his personal debt.
Another possibility is that if it is regarded as the debt of the two of you, the property is given to your parents by you, but it involves the difference between the amount of capital contribution and the mortgage. Mortgage does not change the familiarity with the property, and his pre-marital property is still his. Repayment after marriage is regarded as capital contribution.
You have the right to dispose of the purchased property, but you agree to write his parents' names, which will be regarded as your gift.