You can say this over a cup of tea. "Hera na mero euta saathi bharkhar nai bihe gareko. Usko budi ta lalchi rahicha arko sanga affair gareyra ani mero saathi lai divorce gareyra usko 50% property pani lagecha."  "Kasto zamana ayoh achel ta kaslai biswas garnu pani nahune."

Meanwhile your future wife would be shaking her head and listening intently. Then you change the subject . About a week later while having a cup of tea you can broach the topic like this.(lets assume your gf name is pepsi)  "Pepsi , i have been thinking about this for a while. I think we should go for a pre nup."  :)))