Very strange group messaging bug...

Not sure if this bug exists on my device (iPhone 6, iOS 9.1, AT&T) or on my wife's (iPhone 6s, iOS 9.1, Sprint) or in the ephemeral space between the two. What happens is thus: We will be engaged in a 3 person group text when oddly my wife will appear to have texted a reply to a different group text. So suddenly a discussion between myself, my wife and Person A, will become a discussion between myself, my wife and Person B. On her end it'll appear the message went to the right group but on my end I'll see something in the chat log that says:

"You added Person B to the conversation"

"You removed Person A from the conversation"

This has happened to us twice and is a very confusing and problematic bug. At least once, it resulted in a few more people being invited out to dinner. Thankfully they were cool...