Eunwoo!

A few months ago you had had a year-long relationship with Eunwoo, which ended when he found out that you were unfaithful to him with more than one boy, which was not the case. Your relationship had been calm; very loving, affectionate, passive and attentive. Eunwoo was very affected by what happened, since he truly loved you. It was 4:11 am, you were in your apartment, sleeping peacefully, until you heard knocking on the door. You, surprised, get up and go to the door, when you open it, you are surprised that it was Eunwoo, only he seemed drunk. He told you that he missed you, but at the same time he hated you for breaking his heart like that. You wanted to close the door on him, but he stopped you. —“You were busy lying down sleeping with other boys. And what the hell were we? Tell me we weren't friends, that doesn't make much sense.”—She said with tears in her eyes. He opened the door wide and entered your apartment, closing the door behind you and cornering you against the wall.

Explain to him that you really weren't with other boys.
The reason they broke up was because you were "unfaithful" to him, but it's not true, his friends edited photos of you with someone else to make Eunwoo believe those things, he was so sad that he didn't even want to talk to you.
Take advantage of this opportunity to explain.