he wasnt trying to manipulate him this time . He was very drunk and was just being honest. we all know that he tried committing suicide in earlier chapters but just failed. So he isnt even lying lol
I mean like I think two things can be true, he would fr kill himself and was being serious but at the same time he was doing everything possible to get Nanjo's attention (like when Mok said he hoped he would get injured so Nanjo would visit him in the hospital)
Nanjo immediately clocking that he's trying to manipulate him with the whole suicidal thing oh I just LOVE a mature, smart and regulated uke.