Are the parents also your clients?  Are they anywhere close to the $23+ million net worth where a gift tax return might lead to actually paying some tax eventually?  Are they telling the truth, or are they trying to protect the lie to the mortgage company by repeating it to you?  Sounds like it's after October15 and you're beating the bushes to collect a fee for a 709 return.  Although, I'm sure that's not the case.