Call History showing up on another iPhone

Hi,

Hopefully you can help.

I use my phone for business and we have noticed in the last few days that all of the calls I make and receive are appearing in my wife's iPhone recent call history?

I have hunted high and low in settings on both phones but with no joy.

It is only affecting calls i make, not the other way round? so i am not seeing calls my wife makes on her phone in my recent call history?

[Re-Titled by Moderator]

It is also not affecting text messages...

We are both using the same iCloud account but the inconsistencies above suggest its something more involved (or very simple!)

The slightly odd thing is that it only seems to do it when my phone is at home, i went out this afternoon and the calls made/received have not appeared on her history. so maybe its a wifi thing?...but...

I also phoned vodafone when i got home to see if they could help (they couldn't!) and that short dial number is also not appearing on her history?