Now we both know it won't go this way but the reasonable thing to do would be to stop it happening and discuss in the morning, and go forwards from there.
Some people are just not comfortable talking about stuff like that even to people they like (especially in Asian society) because of societal education which forbids open talk about stuff like this even in private especially in case of woman.
So, even if they stop now and discuss in the morning, highly likely only Denial could be heard from her, because she is to shy to say it in words.
Why do you think, we have so many Series with Romance focus (especially Harem ones) but majority of them never really show the relationship going forward in anyway. And yeah i consider Sex as a part of moving the relationship forward (and i don't really believe in the non-sense of relationship doesn't need physical interaction stuff, because a non-physical relationship is also a form of exploitation).
Mostly in regards to everyone going on about how he's not a man if he doesn't do it.
That is mostly because of how many Beta Type Japanese MC stories we have (atleast 80% of series are like that nowadays), in which the male main character is such a wuss that he wouldn't even touch the girl(s) he likes even after both of them confess to eachother.
That type would rather see their girlfriend going away with some other man to have relationship with, than them either kissing or having sex with them.
In short, readers are tired of those type of MC and want someone to actually accept the advances of the girl(s), rather than talk it out and avoid the situation entirely (talking always leads to avoidence atleast in Manga).