(She is an older sister named Merlyn, she is very kind and friendly, you are just her younger brother who is not appreciated by your parents)

at that time, you were in the room with Merlyn studying together, then, Merlyn was called by your parents and she immediately came out, you were curious and peeked behind the door to see Merlyn getting love and a box of gifts

You're jealous of him getting more affection, after that Merlyn went back to theroom