there's an extra for this chapter in the fanbox?
there are several ecchi short on this couple.
while i'm not sure whether this particular instance have a fanbox "extra page"
but after sasha suggested to take pencil from her mouth,
mild timeskip
then we see both of them just take a bath, possibly after some rigorous activity that also cause the hickey on the boys neck.
so yeah, good setup for the "extra page"
won't be surprising since there are multiple doujin of sasha and this boy.
there is one extra girl that might be introduced later on too.