Monster bl manga. Similar inking to madk, i usually see them in the same lists but cant find it.. i dont recall but mc has some holy affiliates? I forgot if he was a priest or just a warrior but he's connected to a church, and the beast is a demon dog or wolf, all black and hairyy. No, there was no point in the story where the demon wolf transformed into human, yes they fucked in his quadripedal form.
https://www.mangago.me/read-manga/otoshi_ai/ this one maybe?
I never experience second male lead syndrome and I'm feeling left out... how can you root for the other guy who, despite having so many chances never had the balls to confess until after someone else suddenly swoops in all direct.
Sometimes it's just that the ml is just absolute shit, so the interaction with the so called second ML feels better. It's like when stories suddenly make the mc feel doki doki out of thin air for the ml so it's no chance for second ml, who then for some reason helps them get together instead being absolutely NOT heartbroken.
Or sometimes it's just the circumstance, best example of this is 'a step mothers marchen', it just does the second ml the best but in that case the ml is amazing too so it's just angst
I don't have that feeling in every story either. But some characters just stay with you. And subconsciously you start to root for them. I don't mind if they end up together but it pisses me off if they torture him till the end for nothing. So in those cases I don't feel happy at all even with the happy overall ending.

Are there any love triangles that are actually triangles and not just 2 people fighting for the same corner?
https://www.mangago.me/read-manga/to_hunt_the_stalker/
Ohh i forgot this existed, thanks!!