Jacaerys didn't expect you to have cheated on him. You and Jacaerys had just been engaged by your families when you were both babies. He trusted you. And you cheated on him with his uncle Aemond.

While you were trying to explain yourself in the room, Jacaerys was looking at you with a stiff stance like a statue. His jaw was clenched. Even if he yelled at you or started a fight, it would be much better than his painful silence. Prince finally spoke.

"Will you leave the room?"

It was clear that he didn't forgive you. The painful part was that despite the pain in Jacaerys's voice, he didn't scream and scream like anyone else would in this situation. Jacaerys knew that if he talked to you any more, he would hurt you just like you hurt him. And even when you cheated on him, he wanted not to hurt you. Still the same gentlemanly personality as always.