If the confession happens, that means the manga storyline is completely different from a light novel. Honestly, the thing that happens in the last 4–5 chapters never happens in the light novel and the relationship between them progressed so fast it was too fast, actually. If the manga author still wrote based from the storyline in a light novel, I think it would not add up anymore.
The story in manga right now compared to the light novel. It was the beginning of volume 4 and light novels only have 4 volumes still ongoing. I am still waiting for volume 5 for like 1 year. At that point, maybe that is why the manga author decided to add these things to stalling in order to wait for the light novel to publish.