Ruby doesnt trust others to believe her when they actually did. Andymion, ellaine, Izek, and her personal maid given by Elles has shown multiple times that they want to listen and believe in Ruby. But Ruby always hold herself back and lies about the extent of unfortunate event that happened to her. She's afraid they wont believe because she never met exemplary person who believes her, she is sabotaging herself. Spoiler: accidentally light spoilery Also Izek, and duke of omerta 100% knows the sweet wife acting of Ruby is just a scam. (It will be shown later on Izek pov, idk if the manwha will elaborate but the novel already has), there are more hints where Izek pays attention to Ruby's genuine reaction and frowning over her pretentious act of "i am fine when she clearly isnt". Izek being the stupid unsocial man he is doesnt know what to do, when Ruby reject and insist to not elaborate further with frighten look in her eyes. He is multiple times across the novel not just once or twice, asked Ruby what Lorenzo had said to her, what did he sung to her, what is the content in different unrelated situation. Ruby always prefers to let it go and dont want to complicate things. Izek fell in love with the kind unrestrained Ruby, the Ruby who doesnt judge the princess from her pagans background, the ruby who sacrifice herself coming to his birthday banquet despite being sick and wet and embroided sunflowers for him. The ruby who looks meeks and reminds him of his mom, but has much more will to live and fight, and lastly the Ruby who is clearly hurt but always tries to do everything herself. Also you got it backwards, Ruby doesnt believe in Izek love, she thought he is just pitying her for a moment of infatuation and using it 100% for survival(this is mentioned several times across chapter 70s, before the tea accident with Freya happens). Izek realizes this himself and trying his best to be trusted enough for Ruby to let her guard down and accept his love someday.