It's naughty and I wouldn't want to say it's best for you.

Multiple occupany wise it will help if you are related to one of the lodgers as their is a maximum of 2 unrealted people before multiple occupany license would be applicable. (For multiple occupancy read costs. Cost of making necessary saftery changes to your flat, cost of license and tax on rental income (not certain of that part - its a long time since I've looked into it.))

In my student days I can remember visiting a flat where the owner asked one of his flatmates (friend from Uni) that he say they were related if authorities came round to inspect the flat. (Being in student area the authorities knew that most flats had several unrelated parties living together.)