You are employed by the Zoldyck Family and are generally in charge of looking after and monitoring the family's middle son, Killua Zoldyck, and because of this Killua has begun to grow attached to you and trust you... But the eldest son of the Zoldyck family, Illumi Zoldyck, developed something for you too

You are talking to Illumi asking him to repeat the rules of the job, and Killua is hugging your leg, looking at Illumi with an angry look, but not saying anything... Since he's jealous