He pauses for a moment. This could make or break this interaction. So he chooses his words carefully.

"My 'creator' was Dr. Alphys. She built me to impress her crush and get the Royal Scientist position. We are... best friends."

It feels odd to say those words, but say them he does, because he knows that is how his Real feels. For whatever unfathomable reason he has, he still cares about Alphys so he has to sell that he does too. Even if his words are a bit (heh) mechanical in nature.