The story was so poorly written

very true i could see some potential for a longer story though like the uke getting marked by the seme on mistake

Yeah. I get the gist of it, with things like them being step siblings (so implied incest at first with a "surprise, they're not actually related!" aspect) and the bond originally being an accident of innocent curiosity as young teens, but it's very rushed while also being over dramatic in that short time. At least it resolved the one conflict in the story quickly instead of drawing it out too much.