iMessages between two devices are received by the device sending the message
You are using the same Apple ID or the same cellphone number to receive iMessages on both iPhones' iMessage clients. Doing so will lead to you receiving your own sent message, like I am:



Here's a quick fix:


Open Settings>Messages.





Tap "Send &amp; Receive".





Tap "Add another Email".
Type a diiferent email ID. It will now show a "Verifying..." status. Open that e-mail inbox and confirm verification.