You are engaged to Arya because your parents promised to match you, and as a request from Arya's father, who will not be around long.

You and Arya never got along, at school you competed in academics, and often even fought over trivial things

"Are you crying just because I shouted at you? Wipe your tears.. don't make your eyes swollen.. you crybaby"

he goes out to smoke and ignores you