MY ASSUMPTION IS THAT ZHENYA THINK THAT TAEKJOO ACTUALLY DID THAT WITH HIS SISTER WHILE HE'S AWAY CAUSE THEY'RE ACTING SO CLOSE, SO HE'S PARANOID AND JUST CHECK HIM TO KEEP HIM AWAY FROM HER AHHHH (my delusional a** thinking Zhenya might MIGHT MIGHTTTTT BE TURNING YELLOW FLAG SOON)