Responses
I think you forgot Mathew knew Hayoung was interested in him because he couldn't stop staring at him. He manipulated Hayoung into moving into the apartment and helping him with his heat.
I get it he likes him but as a LAWYER he should have a way with words. Not use his pheromones on Hayoung into submission.
And if he can help Jaeho why he couldn't ask Jaeho or Ian to set him up with Hayoung?
I always knew seme in omegaverse can be really too much but as for Matthew, I think he's just overly in love with his omega. I've read lots of omegaverse and seriously his action is just one of the things an alpha can do so I'm not viewing it as him being a psychopath or something. And I'm not saying this to tell you that I'm fine with it!
I just want to explain that Matthew here is not that bad, considering this is omegaverse and he was in his rut plus jealousy. Ian and Jaeho on the other hand is different so we can't compare the two alpha. In the first place Jaeho and Matthew has a different situation.
As for being manipulative, no Matthew didn't hide/get Hayoung's phone. His obsession shows that he finally lost it from trying to hold and wait to get on Hayoung's side. Remember that Matthew said that he knew Hayoung is his mate from the very first time he saw him. I also want to clear that Matthew never like Ian. He did it for Jaeho. He said it too when Ian learned Matthew is an alpha too, he explained it briefly. As for the things he told Hayoung after, it's probably his way to check if Hayoung cares if he has a slightest interest to him. A way to check if he has a chance.
Keep in mind that Matthew has been suppressing and waiting for Hayoung though he somehow got a chance to get physical with him thru their heat cycle. But it's not force alright so there's no issue about it. Btw this is getting longer so Imma stop now lol