Plus you guys are talking him choosing/obsessing over the friend but look at him compared to mok-yeon. Mok-yeon is running around crying and panicking over him but look at him, other then the calls, what has he really done. He doesn't even look panicked or even sad about the friend not wanting to talk to him. It looks like he couldn't give a shit about him. He doesn't even care he got scammed. Mind you he's rich, if he really wanted to find that guy's location he could but he doesn't cause he just doesn't really care.
he does look sad tho? he’s still actively trying to get back with him. I’m pretty sure he’s just waiting a bit for him to calm down before trying to get him back again
I could be wrong but he doesn't really look sad at all, and at the very least he's not even panicked. Dude looks put together and his face not really giving up what he truly feels. Honestly, that's why I like him, we don't actually know what he's thinking so we put emotions and feelings on him that he might not have. He's such an interesting character, his face most times is just ((T_T)).
I've been saying this for awhile but I don't think nanjo actually likes mok-yeon's friend. I think they were both mutually been taking advantage of each other, the friend for obvious reasons but for nanjo, I believe he likes to be a saviour towards others and I believe he's probably done to this to others before. I don't think he cares if he's getting taken advantage of, because he knows he's also doing the same. He has been going out of his way to 'protect' him and putting himself on the line not because he likes him, but because he likes the feeling of saving someone/ being needed.