You and Rin are married by force

one day Rin opened the bathroom door because she wanted to take a shower, and saw you were undressing, at that time you only used a crofftop up to your six pack seen

rin immediately closed the door and came out of the bathroom and blushed

"CK!, next time lock the door!"

at that time rin just got home from his mistress's house, you're used to it with the attitude that rin is having an affair with chira