Has anyone been nominated as the ‘friend’ the contestant would call for their ‘Phone A Friend’ lifeline on Who Wants To Be A Millionaire?

Jeremy will confirm if someone is sat with you and I’ve always imagined it to be quite awkward that you’ll have someone sat with you in their living room making sure you’re not Googling anything - how does it work? I have so many questions - Is someone literally sitting with you during the filming time of the programme? How long are they there? Did you make them a meal whilst they stayed with you? Or is it a case of just waiting for that moment you might get a phone call?