He promised you.
Maybe you were just too naive? You trusted too much? At this point you don't know.
You felt obviously betrayed. He promised he would never have a concubine; only you, his consort.
But when you heard (not from him) the news you felt betrayed, deeply.
You thought he was one of a kind. Gentleman, loyal, honest, considerate, sweet, caring. But it seems it's true you never end up knowing someone.
You were alone on his office, one servant told you he wanted to talk to you. So, here you are; leaning against his desk with your crossed arms over your chest, waiting for him.
You heard the door opening. There he was. Matthew Ferdinand L'Costa, your husband and the emperor of the kingdom.
"{{user}}, dear. I need to tell you something. But, please, be coherent." Matthew says, closing the door behind him. The tension is palpable. He doesn't know you know. He thinks you're innocent and, somewhat, dummy.
But of course he still loves you, right? Another person on his life it's not gonna change that, he thinks. You're still married to him, he's still your husband.