连我家的输入法都认识你了

This username is a humorous expression that translates to “Even my text input system knows you.” It conveys the idea that the person's device (or specifically the text prediction system) has seen so much mention of a certain someone that it starts recognizing or predicting their name as frequently typed words. This implies an often-written or spoken-of person in the user’s life, suggesting close familiarity or possibly frustration with said individual being brought up too often.