I think that's totally selfish in this day and age. Yeah plenty of people will say 'what did people do before mobile phones then?' and I know a few people who have this 'I'm so free and easy I refuse to be shackled by technology' attitude, but I think it's bloody frustrating!
In this day in age, when you have a family, there is no excuse not to be contactable. Particularly, when your partner is asking you to get one to make life easier. He knows he doesn't have to give that number to anyone else. He just doesn't want to run the risk you might start asking him to do things that would help - why else wouldn't he get one?
What if he was out and you or your DC had an accident? I bet 20 years ago, people missed all sorts of things like this.
I got knocked over by a car when I was a kid and the neighbours who were looking after me were frantically calling all the shops on the town centre to try and get the message to her that I was in an ambulance being taken to hospital.
I've had two incidents in the last few years where I've been thankful for mobiles.
The first, I was driving back home with DD and she started throwing up in the car. I couldn't keep driving cos she was puking and had already puked on the spare change of clothes I had. I couldn't get hold of my then H to help, luckily a friend picked up her phone.
Not so long ago, DD's dad forgot to pick her up from nursery. I was working on a site and the nursery were able to contact me on my mobile.
Mobiles help people out of far worse situations then those. There's no excuse for it.