Well, the last chapter was about when he (allegedly) cheats on you (read that chapter so you will understand this one!)... so Y/N is pretty mad now and has stayed away.

-He's fine during the day

-He goes to the gym and works out, which keeps his mind off of it

-At night, though, he lies in bed and his heart aches

-A few tears trickle down his cheek as he fights sadness and tries to sleep

-He resolves he won't do any more favors for Mito that involve older women

-He calls her the next day and explains what happened, and Mito is very apologetic and offers to call you and try to patch things up

-Realizes he misses you

-Grits his teeth because he WASN'T cheating on you, that was just his little brother at the skate park he was putting his arm around

-Kalluto was having a problem with the Troupe members and came to Killua for advice, he was all upset, so Kil was just being a good big brother and comforting him

-(You didn't recognize Kalluto because he had his hair back in a small ponytail)

-Alternates between being angry "I didn't do anything!" and sad "I miss Y/N so much"

-Scribbles out your initials that he drew on his skateboard

-Tells himself he is an assassin and has dealt with way worse pain than this nonsense

-Breaks down and calls you the next day

-Tells himself he shouldn't have led his coworker on

-His eyes turned red that night because he was feeling all sorts of weird emotions...guilt and a little bit of lust

-He doesn't blame you for being mad

-Takes a cool, rational approach: "I'll just forget about Y/N for right now"

-Throws himself into work so he is too busy to think

-Comes home at night and is depressed and sad

-Wakes up again in the morning and determinedly puts on a happy face

-Curses himself for being stupid and making out with that nurse

-But she was coming on to him so hard!

-Stomps around his house cursing and kicking things

-Settles down to watch a show

-He remembers it's your favorite show and starts to bawl

-Gets angry again and pours himself a drink

-He alternates between crying and drinking all night

-Business as usual

-He doesn't belong to anything or anyone

-Could literally not care less if he ever hears from you again

-He doesn't understand why you are so angry

-All he was doing in the park that day was taking a short break

-He sat down to rest for a few minutes and an attractive stranger sat down next to him

-Illumi being Illumi, he was like "What do you want from me?"

-The stranger told him he had beautiful hair and reached out to touch it

-Illumi didn't care, he was like "whatever, I know," but he excused himself shortly after

-He tells himself, oh well, Y/N will get over it, or not...it's not his issue

-At night in bed, he feels the most unfamiliar sensation of emptiness

-Chrollo knows he fucked up bad

-He shrugs it off though. He's a world class villain and he's not about to be tied down to anyone

-He deletes your contacts from his phone and social media

-Spends the evening flirting on DMs with 10 or 11 brand-new girls he just met

-Goes to bed and can't sleep

-Gets up, switches on the light, and tries reading for a couple hours to see if that will chill him out

-He's still agitated

-"Damnit to hell, Y/N!" he snaps. "I miss you"

-Feitan maintains complete radio silence for a little while

-He's taken aback you found out about his kinky escapade

-After a couple days, he starts forwarding you various articles explaining sexual fetishes and how they can be worked into a healthy relationship with both partners' approval

-You refuse to answer

-He finally takes a knife, knicks himself under one eye causing a drop of blood to run down his face like a teardrop

-He takes a selfie of this and sends it to you

-He should have known better than to get frisky with a fellow Spider, that was so dumb

-He mopes around for days

-Shizuku says, "Look, want me to text or call her and try to explain this? We didn't really do that much."

-He says no, that'll just make things worse

-He ends up going to your place and sitting outside, looking mournfully up at your window, until you finally break down and let him inside