My mate is 30 with enough money to get a solid down payment (and over it) and the rest mortgage. However, he met some Chinese girl at 25 and they kind of toy with the idea for marriage soon based on what he told me.

She came to London, UK for University and works now having finished. When she started her job her parents (both in China, possibly some CCP overlords) bought her a 3bed house for like 800k GBP without a mortgage.

Now, I asked him what I will ask you below but he says he hasn't thought about it. He only said that he has moved in with her.

The girl is quite decent tbf but I would assume her parents will keep that house outside the marriage (it will have been acquired before anyway). Then, she would probably expect him to contribute towards bills and married couple life (especially after a kid shows up) a lot more.

Wouldn't that erode his possibility to purchase something for his own equity? Because, in the event of a marriage breakdown, where would he go?

Either she has to agree for him to purchase something to have which in best case scenario will be an investment property that she owns 50% of?