Hello zaparuxi,
Thanks for posting. If we understand correctly, you might have a question about using the emoji keyboard on your iPhone. We'll be happy to help out, and we'd like to get started by getting some information about what's happening.
When you say the couples emoji is the default, what exactly is happening? Are you saying you sent a "couple" emoji and now see it under the "Frequently Used" section of the emoji keyboard? If so, this is normal, and the emoji you see in that section will vary over time. It's possible to reset these emoji by tapping Settings > General > Reset > Reset > Reset Keyboard Dictionary. Keep in mind though that this will also remove any custom words you've typed, and it resets the keyboard dictionary to factory defaults.
If this isn't what you're experiencing, let us know the details. Take care!