Person A bought an expensive iPhone, but failed to furnish it with a protective screen cover, case and insurance
Person A brought expensive unprotected uninsured iPhone on a boozy night out
Person A brought no bag or jacket with pockets with which to carry expensive unprotected uninsured iPhone on said boozy night out
Person A got heavily inebriated, at the financial expense of Person B, whilst in possession of expensive iPhone, without any means of storing it
Person A then got bored of carrying their own expensive unprotected uninsured iPhone around once the battery died so, asked Person B, also intoxicated, to take it off her hands
Person B felt obliged, being a nice person, but accidentally dropped Person A's iPhone whilst kindly carrying it around in his own pocket, because being a nice chap he didn't want to get into trouble with the law for being in possession of a car and it's keys whilst intoxicated
Person A then demands Person B pays for its repair, AND a takeaway, AND a weekend away.
Person B needs to locate their spine and tell Person A to come back when they've learnt some responsibility and maturity. And "see you on Judge Rinder!"
I can only assume Person A must be very good looking / fit / good in the bedroom dept for your DS to take this kind of freeloading