He is unintentionally manipulative. He isn't doing an act, threatening Nanjo to be with him. He genuinely is feeling that way. I don't know Author's intentions but she lowk cooked a good enough bpd character
(Now I just hope this does not end w Mokyeon being magically cured because "Nanjo gave him a chance" and he actually seeks therapy, that'll be quite refreshing to read)
Isn't this the one where the bottom buys a HUGE ASS DILDO AND TRIES TO INSERT IT BWHAHAHAHAHAHAHAHHAHAHHAAHA I remember reading this on bato, completely forgot about it