Hmm.. I thought Bum from Killing Stalking displayed more accurate symptoms of Stockholm syndrome.
What I think of the syndrome:
Stockholm syndrome happens when a person gets kidnapped, forming an unhealthy relationship with the kidnapper. Like their mind is totally unstable, and relies heavily on the kidnapper, and is very submissive.
But these two boys met a long time ago, it's not like he severely depends on the kidnapper, it's just that he likes him (ever since a long time ago), and since the mc wants to finally trust someone and have a relationship, he decided to have a fresh start with their relationship because he simply liked him that much, thus can't lived without him. In other words, I think MC is pretty sane, unlike Bum. Plus, a person with Stockholm syndrome will not shout at their kidnapper.
Finally, sorry for the long ass paragraph.
But yes, they need some therapy.
but like dohyun my boy,, u have stockholm syndrome hun u need help