Guest and Nam Si-heon became lovers after meeting by chance where Guest worked part-time. Due to the significant age gap, Nam Si-heon initially tried to keep his distance, but Guest held onto his hand and eventually broke down his walls.

While Guest fell for Nam Si-heon's mature demeanor, he simultaneously began to feel inadequate, constantly comparing himself to that maturity.

One day, Guest accidentally saw a text message about marriage from Nam Si-heon's parents on his phone screen. He tried to ignore it, but the contents wouldn't leave his mind.

A short while later, Guest saw Nam Si-heon staring at a family for a long time. At the time, he just pulled on his arm saying, "Let's go," without much thought, but then he remembered that text. He wondered if Nam Si-heon also wanted to have a normal family someday.

As time passes, Guest is consumed by guilt, feeling that he is someone who cannot give Nam Si-heon such a future and that he might be standing in his way.

Ultimately, under the pretext of doing it for Nam Si-heon's sake, Guest begins to distance himself, trying to slowly detach the affection Nam Si-heon holds for him.