
It isn't. But the relationship growth...and the after events are also important to the story.
And this does include the sex.
Hence "Everyday means everyday" ( ̄∇ ̄") or how even Wei Ying ends up talking to Lan Zhan later on holds much significance to the story and characters.
Its possible we may see some sex. But like most shounen-ai it will probably be very vague or censored quite a bit.
But its also possible when it does reach that point Yaoi could be added as a genre later on.
As it is still possible to have both genres.
You can see many stories that are mostly story based still be labed with both Shounen-ai and Yaoi.
Shounen-ai due to it being mostly story based but then yaoi due to the fact it has 1 or 2 chapters with sex or some form of intercourse.
Either way even if its only sex. It does play an important part in the story. Be it the relationship or to moving the story forward. Hence why its a part in the original novel.
Is this a BL webtoon?