Episode 6 shed some light with PJE's thoughts. He believes that certainty in relationships makes them weak. BUT, it's not like, that level of uncertainty strengthens it either. 

From the conversation bw Jaeon & Kyuhyun, since they seem to mirror the other's partner, Kyuhyun and Nabi both do not like this uncertainty, but had never honestly conveyed their expectations on exclusivity to their partner especially that Jaeon expressed his avoidance to a labeled relationship.

 Nevertheless, I think that having that kind of relationship with PJE is really unhealthy especially if deep inside you are expecting for that exclusivity to happen someday which is uncertain itself.

It's okay and I even understand Jae eon's side at some points. And I think the problem starts when he's not really clear on what he wants. For example, if she had told Nabi that he just wanted a "casual sex" or "friendship with benefits" then ok, it would be her problem not to realize that he doesn't want commitment, that would be her being stupid, however, the problem starts when he doesn't draw that real line about what he thinks and wants.

Nabi has to decipher what HE wants, and here she is being an idiot and stuck in something that makes her insecure and anxious, because if you know, you've heard and you can witness that the person is a red flag and yet you " continues" giving margin, you need to review your concepts about relationships.

Jae Eon wouldn't rub me the wrong way if he was totally forthright and let her know what he was looking for in the beginning (as a lot of people do in the real world, or at least the people that I've dated). But he has been intentionally manipulative, outright lying to her on several occasions to make her think that he's not seeing anyone else.

He is a red flag because while he claims to want a FWB relationship, he is acting the opposite way, making her feel cared for. Notice that every time Nabi tries to break things off or starts to pull away, he starts acting really nice.  

FWB do not give each other gifts, they do not cuddle, they do not go one dates.

If he wants to be FWB, he can make that clear but he is purposefully blurring the line for Nabi so that she keeps coming back. Then when she wants more, he immediately draws the line and it becomes her fault. That is not how someone who wants an open relationship behaves. He's manipulating her because he knows he can. 

Many people seem to think this is because of his attractiveness but it really isn't. It is his charm. Attractiveness alone is not enough to string so many girls along.

@Anofferhecantrefuse said he isn't your typical jerk who hides behind a constructed personality to attract and deceive people for achievements and gains but I have to say, really? 

Because from what I can see, Park Jae Eon seems to enjoy the thrill of the chase. He enjoys seeing these women bend over with a little twitch of his fingers. After Nabi and that junior end things, PJE tries to win her back and his behavior is eerily similar to that junior for a while. He saw that Nabi was attracted to the junior and acted in similar manner so that she crawls back into his net. In fact, he does this right after the junior rejects Nabi and she's feeling a little vulnerable, how is that not deception?

Well this has been longer than I thought it would be but these are my thoughts. 

I agree with Anne-Marie . A FWB doesn't show up to your aunt's house and basically tells her they ate together at her house. He totally enjoys her reaction and enjoys the fact that he can manipulate her, that's why he asked Do Hyuk that question in episode 8, while smiling. He knew the answer. He knows her vulnerabilities, weaknesses and uses them. 

I came here looking for other opinions on PJE's behaviour, because in the last episodes of the drama he kept getting on my nerves for some reason and I thought maybe I was being biased, but I guess not lol. I totally agree with what both @Anne-Marie and @emmagucci said.

I get that PJE has his own issues and that he doesn't want to be in a relationship, but if you state that from the beginning, then act on your words. If you are only FWB and don't want/expect to be anything else, then you have to assume and move on if the other person wants something else or wants to date someone else. But PJE kept leading Nabi on, then didn't pay her attention when it was convenient, and when she finally draws the line and says enough is enough, suddenly he misses her so much and says he kept thinking of her *eye roll*. He looks like the kind of person who doesn't want to commit, but doesn't want the other party to be with anyone else. How's that fair?

(SPOILERS of eps 7-8)

I hated eps 7 and 8 so much because of that. Dohyuk was soooo nice to Nabi, paid her attention, genuinely cared for her and tried to cheer her up, only for PJE to come and mess with her again. Not only that, like @emmagucci said, he basically appeared in her aunt's workshop early in the morning to corner her again, like wtf, know your place (also, if her aunt knew Nabi so well, she should have clearly noticed she was openly uncomfortable and shouldn't have invited him to eat with them afterwards, to be honest). I don't think PJE is evil or a bad person, but he is definitely manipulative and knows how to use other people's strong and weak points to his benefit.

An article on Cosmopolitan (PH) basically said the same thing,

Quote: 

"All The Red Flags We See In K-Dramas
The Flirt “With No Strings Attached”
As seen in: Nevertheless (available on Netflix)
Flirts are okay, TBH—but if hindi mo papanindigan? Not cool. Park Jae Eon, Song Kang’s character in Nevertheless, has spun countless memes and tweets. His flirting powers definitely put a new meaning to seeing butterflies. But we can’t discount all the warning signs he’s shown since the pilot episode.
The guy was actually there to meet another woman, supposedly. Instead, he decided to spend time with Na Bi (Han So Hee). What if you were the other girl? He also recycles swoon-worthy moves, doesn’t DTR, and doesn’t admit to seeing you when asked by others. To be clear though, we respect people who prefer casual dating and open relationships—do your thing. But if you’re going to lie about it and make one of the people you’re stringing along think that she’s you’re one and only? Boy, bye."(end quote)

It is clear to us, the viewers, that he doesn't want a relationship for whatever reason. But from Na Bi's pov, the way he is hot and then cold, sometimes acting like a boyfriend but then drawing the line like she said, gives mixed signals and is actually not clear communication to Na Bi. 

 emmagucci:

An article on Cosmopolitan (PH) basically said the same thing,

Quote: 

"All The Red Flags We See In K-Dramas
The Flirt “With No Strings Attached”
As seen in: Nevertheless (available on Netflix)
Flirts are okay, TBH—but if hindi mo papanindigan? Not cool. Park Jae Eon, Song Kang’s character in Nevertheless, has spun countless memes and tweets. His flirting powers definitely put a new meaning to seeing butterflies. But we can’t discount all the warning signs he’s shown since the pilot episode.
The guy was actually there to meet another woman, supposedly. Instead, he decided to spend time with Na Bi (Han So Hee). What if you were the other girl? He also recycles swoon-worthy moves, doesn’t DTR, and doesn’t admit to seeing you when asked by others. To be clear though, we respect people who prefer casual dating and open relationships—do your thing. But if you’re going to lie about it and make one of the people you’re stringing along think that she’s you’re one and only? Boy, bye."(end quote)

That was a good way of putting it. TBH red flags are hard to see unless you've learnt to look out for them. If I had watched this drama before I learnt about red flags in men I don't think I would've seen any either. 

I agree with Anne-Marie !! Actually that thing he does- where he starts acting really nice when Na Bi seems to slip away from him, is a common trait of narcissistic relationships. As is fireworks on the first meeting and the first few times after that, which Na Bi definitely admits to feeling (especially compared to the guy younger than her and potato guy). I'm not saying Jae Eon is a narc but he is not innocent in his behavior. I recommend reading about narcissistic relationships and watching youtube videos on them, they're really informative on red flags to avoid. 

SPOILERS OF EP 9 (about PJE's attitude and other issues)

Finally in this ep we see the relationship between PJE and Nabi "explode" and I think we can see PJE's true colours. When they argue under the pouring rain and he starts acting like a jealous jerk and asks Nabi if that isn't what she wanted, referring to them going out, I almost flipped. So basically, early in the ep, he asks her to go out with him just because he thinks that's what she wants! I mean, he thinks it is the only way to keep her tied to him because he feels threatened by Donghyuk, who is a much more stable, caring and open person. I was soooo glad that Nabi fired back at him in that moment and didn't back off.

In the beginning I found Nabi and PJE's "relationship" nice and I thought it was kind of fresh to see a friends-with-benefits dynamic in a drama, where everything is usually focused on love, romance and destiny. So, if they are going to keep it realistic again, Nabi shouldn't end up with PJE. That kind of relationship is bound to end sooner or later, like it happens in real life. I don't think Nabi ending with PJE would prove a good example for any woman watching the drama... I don't mean that she needs to date Donghyuk at the end, but more like she should just focus on herself and find her own happiness and inspiration however is best for her.

PS: Great insight in all your previous comments! I totally agree with the Cosmopolitan article that @emmagucci quoted.

ok idk if any of you remember but he has mommy issues. just like how some girls have daddy issues. So because of that he is scared to be attached to any woman. which makes him the type to have commitment issues. He's not a jerk or a toxic egotistic bad boy that you all claim him to be. He show and told her his intentions in the beginning and she tagged along (her fault). He's just a sexy ass man whos scared to commit because he doesn't want her(whoever he ends up with any random girl) to end up leaving him alone like his mom did. Also towards the last eps you could tell he was really hoping nabi would be that girl that'd stay.... (tear drop... me crying silently for him....) but i havent seen the last ep so i shouldnt assume that last part. Anyways all in all this is my opinion from what ive seen so far you dont have to agree but most prob will. dont hate either plz. 

P.S.

P.J.E IF YOUR EVER IN MINNESOTA CALL ME I DEFINITLEY DONT WANT COMMITMENT AND WOULD LOVE TO HAVE ME SOME OF THAT.....HMPHH....excuse my language... lmao....