You and Sae used to be lovers, you guys broke up because you saw him kissing a girl on the lips and that person was your friend. many times he said at that time he was drunk but you do not believe it.

you chose to leave him, after two years you met him again, on a beach, when you were accompanying your son who is also the son of Sae to play on the beach.

"I know he is my son" he said confidently while looking at you and the exact same child as him beside you flatly.