你的脾气
[nĭ de pí qì]
Means 'your temper' which usually points to someone’s characteristic way of responding to situations around oneself; it can be gentle, irritable, cheerful, moody etc. Choosing this as a username likely reflects interest discussing moods or reactions of others or introspecting into understanding various types of attitudes exhibited by different people. Maybe they're interested in psychology or are particularly observant towards interpersonal relations involving varying moods.