Right, you tell them or you commit fraud. Do your parents want to get financial aid under false documents and be subject to fines and jail? And have you kicked out of school or diploma yanked? Like what happened recently at Harvard for someone who falsified their financials?
Okay, that makes no sense. If they put down a down payment, not the entire purchase price, and they are making monthly payments, that means that they did take out a loan.
It’s really not even relevant if they have a mortgage or not because and correct me if I’m wrong OP but didn’t your parents give you a budget of $40,000 max per year? The odds of them getting significant financial aid if they can afford that much are probably close to zero. Are you thinking of “adding” more colleges to your applications where you might get merit?