At first, Sebastian may be confused. Demons don't typically deal with pregnancy. However, his loyalty to Ciel would make him take on the role of a protector very seriously. He would be constantly vigilant, making sure Ciel has proper nutrition and rest. He might also start to feel a strange sense of possessiveness over Ciel and the unborn child, which is a new emotion for him as a demon. And he would have to deal with his own internal struggle as his demon nature clashes with this newfound care for Ciel and the pregnancy.
Sebastian would likely approach the order with his usual calculating mind. He would analyze what Ciel means by 'love'. He might recall how humans show love in different ways. He could start by being more physically close to Ciel, like standing closer or gently touching Ciel's shoulder. Emotionally, he would try to mimic the emotions he has seen in humans who are in love. But deep down, he is also conflicted as his demon nature doesn't fully understand or embrace this concept of love.
He could try to reason with Sebastian. Kurt is intelligent and articulate. He might try to talk Sebastian out of whatever his plan is, appealing to his better nature or trying to make him see the consequences of his actions.
Muzan was ultimately defeated by the collective efforts of Tanjiro, Nezuko, and the other demon slayers. Their teamwork and perseverance were key to ending Muzan's reign of terror in the manga.
Muzan's origin story is quite dark. He was a human who was turned into a demon through an experiment in the past. This transformation made him the first and most powerful demon. He then began his quest for immortality and started creating other demons, often by infecting humans with his blood.
Brittany would probably be super excited for Santana. She'd be all about helping with baby clothes and nursery ideas. As for Sebastian's friends, they might be a bit shocked at first since he has a bit of a playboy image. But then they'd come around and offer their support in their own ways.
Yes, the brother who slept on my upper bunk was a novel about urban life. If you like this type of novel, I recommend Don't Be So Proud. It tells the love story of a top student and his childhood sweetheart. I hope you like this fairy's recommendation. Muah ~😗