...People... for real now...this manga has been as "pure" as can be in terms of the two MC's relationship.
The "spiciest" moment in their relationship was that ONE time they kissed, besides that, just a LOT of handholding and you think they will "jump" into having sex just like that?.
The chance for them to do something sexual is zero. The chance for the author to be pulling a simple bait cliffhanger is 100%.
"best" case scenario they'll just end up kissing again after 9-10 pages of them being awkward.