The best thing about this is how physically affectionate they are in a myriad of different ways. It's not just simple kissing or sex. It's caressing her hands, hugging her from behind, touching her stomach, fixing her clothing, gently pulling her closer. Lots of gentle loving touches and body language that really shows off their love. It's not sexual as much as it is loving. Then there's all the favors done for each other: breakfast, worrying about appearance, noticing small details, unrequested presents etc. A lot of stories ignore those important parts of showing affection and go for only the easy "big" moments like sex or a confession but relationships are built off a collection of the small things. The little devil is really great with that. It's no wonder our MC falls for her.