User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-25825030-20150411151009

At the end of the 17th volume it is said tha Issei asks Rias if he could talk to her casually in private times. My question is - aren't they talking to each other casually already after the 10th volume when they are a couple?

P.S. I just started to read the Light Novels and I don't mind spoilers