Responses
This is because at the beginning of the story the characters are still in school, so they’re underage. They didn’t make smut scenes because of how young they were, which respect to the author for that. Lots of authors don’t think that much. Later in the story, they graduate and are older, so I would assume that newer chapters will have more smut scenes like the one that’s already be released. You just have to wait for them to be released and or translated.
For those saying this isn’t yaoi. If you would’ve read the whole thing you would’ve found out that only the first half is shounen ai, so you won’t see smut scenes until later chapters.