taku basically also told him is was alright to use him taku knew that haesoo loved someone else but still wanted to try make him fall for him but the in the end heasoo had been loving jowon since the been young there was nothing that could make those feelings go away for them taku was just the person that made heasoo realize his feeling even if if sound bad those two never loved each other they just filled each other sexual need in the time
Nah no one can control haesoos personality as much as joowon did, and vice versa. They might last long for two three four years then saying goodbye. It's just the personalities didn't match well. The reason they have great and spicy chemistry here just bcs one reason, there was joowon in the middle ^^
Honestly, I feel like Haesoo loved Taku in his own way to an extent. But not as much as he yearned and burned for Joowon. He liked Taku alright but it wasn't enough. Let's just say if Joowon wasn't in the picture, he might still be with Taku and they might hv worked out. Not saying this as a Taku fan or anything but that's just my analogy.