When I text my fiance it sometimes turns my message into a group text and includes my old phone number in the conversation. Whoever has my old phone number has responded sometimes and I don't want him/her to keep getting texts that my fiance and I send each other.
I go to contacts and select send message to my fiance and it still sometimes includes my old number when it sends out.
I go to my current conversation thread with my fiance and text in that thread, but it sometimes puts the message in a thread that includes my fiance and my old number.
I've deleted the conversation thread including my old number but it still happens.
It's very annoying; what can I do so that my phone will stop including my old number in texts?
I have a Galaxy S6