Thats an unneccessary comment, gtrfungi...
Adydas: she was talking about her boyfriends car being insured under her name with him as the main driver. In that circumstance the 'may' comment wouldnt be relevant.
The risk with this is that should he have a prang in the car, its YOUR no-claims that will get pinged.
So in effect the insurance company is reducing the cost because YOU are the one taking the risk.
I still think its dodgy; you shouldn't own a car which you can't afford to run/own.