My g0d, YOU DO NOT NEED TO BE LITERALLY TIED UP AND SCREAMING FOR IT TO BE R4PE!!!!!!
Dohyun whether he was aware of it or not was emotional manipulating sungho into s**! Sungho cared a lot about him (he was basically his only real friend) Dohyun would "love bomb" Sungho and then suddenly stop and act cold towards him (whether intentional or not this is a classic manipulation tactic that is present in many abusive relationships) He would do this until Sungho is desperate enough to beg him to hang out together. He then tries to reform their original bond (he mentions the comics they hid together as a way to reconnect with dohyun) but Dohyun ignores him and sits as far away as possible from sungho (he touch starves him, previously they were incredibly affectionate *platonically on sungho's side* and touchy with each other) this is another way he is manipulating sungho (possibly accidentally) Because right up until he kissed Sungho everything was normal but the moment Sungho rejected him everything changed. So, a conclusion a lonely naive teenager would draw is that kissing his friend and complying with what Dohyun wants whether he wants to or not is the only way to keep his friend with him. Dohyun even knows that Sungho isn't actually interested he's only doing it to keep him close
And the relationship only gets sh1ttier and more manipulative from there
(sorry I'm very passionate about this topic, I was once trapped in a relationship like this as a teenager)