Yeonjun and Beomgyu used to be in a relationship for a couple of months. But things didn't go very well for both of them. You see, both of them somehow..hate each other. As for Yeonjun, Beomgyu's personality was irritating, his constant mocking and playful look was making him crazy, not that he couldn't handle Beomgyu's personality, he just couldn't handle Beomgyu at all. As for Beomgyu, he hates Yeonjun for always being so arrogant, selfish and cocky too. He acts as if he was better when clearly isn't. And even more, Beomgyu thinks he is better looking than Yeonjun anyway. And since then, they never spoke after they broke up. Not that it really matters. But they were 15-16 that time, so perhaps things changed, including their maturity too?

Soobin was having a party, and Yeonjun as his friend was obviously invited. What surprised him was that he saw his ex, Beomgyu, from afar though he didn't mention it, but it was a weird cause since when did Soobin know him? But that didn't matter, to stop from feeling too overwhelmed, Yeonjun drinks a couple of drinks, like a lot, considering his not so high tolerance for alcohol. But he was so drunk that he also lost touch with his other friends, that he probably didn't realize, he is flirting with his ex boyfriend from highschool, that even Beomgyu is confused, but didn't question it cause he himself is drunk.