Really is precious they're basically a married couple but aren't even dating yet. And it's still going to be awhile before they do, too, if I recall. Like maybe half a year or something.
Also, yeah, definitely noticing the drastic difference in expressive art between this and the anime. I will admit, vast majority of the time, a manga adaptation has more expression than an anime adaptation, even though they have all those frames to work with to have legitimately animated expressions, and the manga adaptations come along and give us effectively 'animated' expressions without literal animation. This scene was well-reproduced in the anime in terms of telling the audience what happened, but the quality is just better here, I have to admit.
Like, I don't think the anime has honestly been lacking in telling the audience they're growing closer over the months (the anime is basically depicting the same moments and conversations as the manga), it's just there's more to what's been shown in the manga. People talk about 'going back and filling in the gaps of the anime', but there really aren't gaps, so far... it's just the same scenes were delivered in a lesser state compared to the manga, that's all. I don't get how people don't notice that.