We are seeking help from an experienced lawyer for the below. If you know of anyone suitable please let us know. We are lending money to our son as deposit for the purchase of his PPOR. The house and loan from bank will be in his sole name. He is currently single and will potentially get married. The potential partner is happy to sign a prenup (though we have heard this may or may not stand up in court). Son's earning is much more than potential partner. Son is looking for house currently (Sydney). We would like to have a loan document drawn up for assert protection purpose so that in the odd case that his marriage ended ugly and the property had to be sold/ splitted, our $$ would be paid back to us with interest. -We do not need him to pay any on-going interest. - Accumulated interest is to be paid when the house is sold (this is only executed if ugly marriage breakdown, if all goes well, the $$ will really be our gift to them). Son has talked to banks and they said that the private loan is a private agreement they don't need to know. All they know is he has that deposit amount and the bank will proceed normally. Q: would the house need to be mortgaged to us as a second mortgage so our loan to son is legally tied to the house,or just the loan agreement is good enough ?. We don't want to take 2nd mortgage if no-need because we would like him to still be able to take advantage of the equity (as the loan from bank would only be about 30% of the property value). Is what we are after reasonable/ do-able/normal ? Much appreciated any feedback/ advice etc. Thank you.