Perhaps in retrospect we shouldn't be surprised that, as opposed to all of the harem comedies with highschool age or younger kids, the one about the 26ish year old man and the 300ish year old women has them banging within 13 chapters.
Any manga that doesn't milk a will they won't they relationship gets a 10/10 in my book. Wish it was less sudden but hey, better now than 200 chapters later or the end.