Help finding a manga

Okay, so I don’t actually know if it was here in mangago or bato but I’m looking for a manga I thought it was titled “I will not sleep with my husband”. But nothing pops up. First, there’s an age gap between the FL and the lord( don’t know if he’s the ML cause when I saw the manga it only had 2 chapters) on the first chapter tho it open up with the FL and the lord talking and her stating that she will not sleep with him. He sighs and states back now that she’s older they’re expected to have a child and that if they don’t have a child the alliance between her family and him will be void. The rest is flashback and I’ll put in as much detail as I remember. The FL arrives in the lord’s castle as a child bride. The lord gets mad that she’s a kid, I think they send a portrait of her mother saying it was her. She’s grateful that she can get the portrait back, but the lord is upset and walks away but can’t send her away cause their marriage is about alliance. On the first night there the FL was suppose to have dinner with the lord and his people but instead he took a different woman and the FL didn’t know and was about to join them but saw the woman and left. She then thinks about what her mother said about having control by not surrendering herself/ body if her husband has a mistress.
That’s about all I can remember. Hope someone can help me thank you