@xxmkllblncxx Hey, not sure why you deleted your comment on my profile (or if you didn’t, I couldn’t find it). I am the author of Their Pup. That title is actually listed on my profile for the story being on my last account.
But it’s not a story with a poly relationship between werewolf siblings, although there was a scene that had two Were siblings “get together” from an instinctual but unwanted standpoint. The poly relationship was actually with an unrelated Were and their master. So maybe you got the wrong title if you’re certain the sibling relationship is the main romance part of the plot.
In any case, take care! :)