I must say even tho story is good and fluffy, but the way author portrays the seme is some...

I totally agree with you!!! Like though its cute I myself too dont like the seme's behaviour

I completely disagree. They were close friends, he treated Haru in a special way, spent almost all his free time with him, made him a priority over his girlfriends, slept in his bed, even kissed him although he did it in the wrong way. The fact that he didn't go even further and do whatever things you're referring to when you say "he could do things that make him fall for him"* does not mean he didn't really love Haru. He'd already gotten no response after showing how he felt "through his attitude" and getting pushy with the physical contact, so going beyond that and openly courting him wouldn't have made sense, especially since Haru had always identified as straight. (It also wouldn't have worked, Haru didn't realize his feelings until after their friendship fell apart and only figured it out because of that conversation with the other character which happened right before the seme confessed.) Why risk ruining your most important friendship and completely losing the person you love when there's no evidence they might return your feelings? He was right to be worried about that, it's precisely what almost happened when he did confess.

*I don't like the implication of "do things that make him fall for him." You should not manipulate someone into a relationship. I'll give you the benefit of the doubt that you meant "try to woo him."

Also, he wasn't betraying Haru by dating other people. He thought Haru wasn't interested, which he wasn't at the time. It wasn't fair to his partners that he made them a lower priority, but other than that he did nothing wrong. Also, he's living in a very homophobic country where it's much easier to be straight or appear to be. Since Haru wasn't an option and women kept asking him out it makes sense that he'd get a girlfriend.

Completely agree