[SPOILERS]
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Jihan and Jaeun are actually in a relationship not too long afterwards. Siwan, the ex-friend who ghosted Jaeun is an alpha and he's back. Apparently Jaeun and Siwan are fated pairs, Siwan wants Jaeun + Jihan/Jaeun is strange to him since they're (ex) step bros. Jihan isn't too concerned at first but later on, he gets worried and insecure since he can't do anything if Jaeun gets bitten by his fated alpha. At one point, Siwan's dog needs some help in the middle of the night. Jaeun goes to Siwan's house at night for the doctor house call (without telling Jihan btw). Pheromes happened, Siwan BIT Jaeun (thankfully he's not in his heat so they didn't bond). Jaeun freaks out and runs back home, with neck bite still visible.
Jihan is worried when Jaeun comes back cuz he didn't know where he went, and then he saw the neck bite. Suspicions confirmed, insecurity to max, betrayed feeling level 100. Jaeun is still hot and bothered by the pheromone thing that happened and voila, the scene in chapter 1 plays.
That is the point.... we will find out once the story progress.
So Jihan is not an alpha?
Nope, he's a beta that's why he felt incredibly insecure ever since Siwan came back.
So he said those hurtful out of anger,jealousy and probably worry . It’s hard to judge a character based on 1 chapter. Let’s see how this manga develops.
Their relationship seems good so what’s up with chapter 1 where jinan is about to rape him??