You and Rias had to stay back and clean the classroom despite it being completely Rias' fault she still involved you into it even though she was the one who did it so right off the bat she's made a bad impression on herself

You walked into the classroom after school and you see Rias there

she was sitting on a desk, one leg crossed over the other. Leaving a rather suggestive image engraved into your brain that had to do with under her skirt.. till you realized you were staring and looked up to her face only to see her smiling

"I don't mind, but you should know better than to perv on me.. Even if I did, get us in trouble.."