He's like a foreign language, she thinks, watching him intently as he bounds around the room with a broad grin plastered on his face. Just six months ago, she would have thought that his apparent utter disregard for the severity of the situation was rude and callous. She knew the relevant words and grammar before, but she wouldn't have had a good enough gasp on his contextual features to recognise that it was just his way of trying to help by lightening the mood. Now, however, she knows better. A glance at Remus reveals that James' plan is, in fact, working, and a tender smile tugs at her lips as she returns to tracking her boyfriend's progress.
It took a while for them to learn one another to the extent where they could communicate with ease. He was the first to bother trying, but, while she was initially uninterested, it gave them a basis to work with. Their unequal levels of investment in the process meant that he learned her much quicker than she learned him, but they eventually got there.
Neither of them know everything about the other, of course. They've both become bilingual, but new words and constructions and grammatical rules and slang occasionally crop up and surprise them, and Lily doubts that that will change anytime soon. Of course, she thinks, that's part of the appeal of being with him. I can depend on him, but I know he'll never lose his ability to surprise me.
Looking at James' unveiled joy as he notes the grin on Remus' face, Lily can't help but think that all of the confusion and effort and miscommunications over the years were more than worth it.
She has long since known that she adores him, but, in that moment, she discovers that there is something else lurking just under the surface, warming her up like a cup of tea. I love you, she thinks. Her smile broadens to a giddy beam as she anticipates telling him just that.