The authors to a lot of famous coming-of-age books involving romance are often old men. Most notably to my memory is Philip Pullman, author to His Dark Materials. Honestly, I think that if the public can enjoy the writings of 50-80 year old men about teenage romance. Then honestly your work...
Do we know Delkira's parentage? What if Delkira was a former human who ended up turning into a demon. We all know that humans are creatures of desire, and that desire makes a strong demon.
Is this the author releasing all their pent up urges in one release? I really enjoy the mob one but this chapter has left me wholly confused about the author as a whole.
Talking with them is the proper thing to do but I don't think doing a 7 page omake makes it any less abandoned after 5 months. I wouldn't fault him for this.