SPOILERS

Let me set the scene, oh BTW found on a totally Not HENTAI (mind the capslock) website after searching for the authors name.
Fir wants to talk to Nicholas before the account deletion, wants to meet up for Christmas. Nicholas thinking oh the last time to talk with this guy(who he is truly believe thinks as some father figure) agrees for Christmas plans. (Christmas in Japan is a very couples holiday more than the family friendly one which is significant).
Lonnie appears right as Nick agrees, and calls him a bitch and restraints are put on his mouth and limbs. Fir had threatened the police, but Lonnie mentions Fir's real identity and how he's chatting up boys his sons age. If Fir leaves the chat room then he'll release the chat to the public. Nick is raped and turns out Fir had plans to have sex on Christmas. Then Nick faints, but still haven't ended as Nick is gang raped when he wakes up. Even worse it's by people he doesn't know as Fir(digitally) and Lonnie(on the side) watch.
Fir realizes it's who Lonnie is, his own kid and cries. Lonnie been very resentful to his dad for being emotionally neglectful, forcing down promotions even if he meets quotas the dad set, and instead of being with him even once is chatting up camboys his age. Not even sex but just chatting as if they were family when he literally existed(the dad did eventually fuck the camboys and move onto the next one, but the emphasis he has was the talking part). He set up the meeting for revenge, but fell in love for real and was serious about caring for Nicholas as he felt it was "warm and cozy"(google translateand my brain is gonna spot this out). Only to walk into Nicholas agreeing to meet up with his dad irl.