Text message showing up on 2 phones

[gdarwin]

When my wife sends a text message to her father it shows up on her fathers end as being from her and my phone. A copy of the thread shows up on my phone. Its like my phone was copied in the message but it was not. Any ideas how to fix this. Wife phone is a 5s, my phone is a 6+.

 

[klang]

Was your wife's phone previously yours? If so there was something on the apple sites recently about forcing a phone to forget an old number in iMessage.

 

[gdarwin]

Yes it was. I went in and turned off iMessage and Group messaging. Lets see if that stops it. Comments suggest this started with 8.0.