only thinking a way to protect myself.
Separation of assets works both ways for married or live in relationships and protects interests of both partners.Since you are not married bank will charge you extra closing costs and or higher interest rate.Be careful of there fine print like heavy pre-payment penalties.Too bad there is no fixed rate mortgages in Poland or if there are some for 3/5 years only but at higher rate of interest.
For mortgage payments better both open a joint account,transfer money from individual accounts in that account and pay mortgage.I have never taken out a mortgage in Poland but coming from US banking system,Polish banking system sux.
I heard some law in Poland about staying together after certain period is considered like married(common law marriage),we have similar here in NJ in States.(lol alimony becomes Palimony)I am not sure about it in Poland though.
Q:What kind of protection are you thinking for yourself,as I can only see financial??