Call me a whore but

They won't until they're out of the abyss according to the novel. So it will be a while.

Does the story reach it's end by that time kind like dreadful night where they escaped but it ended off out of nowhere??

(SPOILERS)

My memory may be iffy but I think they have non penetrative sex when they’re in the abyss where Hyunmook jerks Yohan off if you need specifics. I don’t think it’s too far away from now.