so how would david and kylie get a mortgage based on their income/job history? They will not be able to put gail's 'rent' down as income as they would have to get a special mortgage that would allow paying boarders surely.
Since they both wori for his brother I assume they'll all just lie like everyone else does on mortgage applications ;-), not really rocket science, you can buy P60 online to say whatever you like and wage slips and 'copy bank staements'. Not very difficult really.