AITA because i'm horrified that my dad wants to have a baby with his new girlfriend?

My parents got divorced two years ago and I took it pretty hard because I was 16. My father is not my biological father, he is my stepfather, but he raised me from the age of 5 and I consider him as my dad. It turned out that he and my mother could not have children, although my dad really wanted to. As a result, after the divorce, they almost immediately found partners. Everything would have been fine, but when I came to visit my dad a year ago, I was shocked to see his new girlfriend and the fact that they had already moved in together. A woman 10 years younger, keratin hair extensions, terrible eyebrow tattoos, eyelashes extensions and at least 5 milliliters in her lips. Then I noticed that nothing moved except her mouth, her entire face was in botox. To be honest, I was shocked, because we always laughed at people like that, and now this, and in our house too. She didn't communicate with me willingly, which I was grateful for, but so you understand, this is the same type of women who ask their husbands "honey, why is the cloud crying?" In short, I was not delighted, but it was not for me to build a relationship with her, I was glad that my dad was happy. A couple of days ago I talked to my dad on the phone and asked what their plans were (they often travel and I meant some kind of trip). Dad answered that they were planning a child. My head exploded at that moment, you see, my dad is 46, they have been together for a year, what child?! Well, I blurted out "horror". Dad was very offended, I immediately apologized, I did not want to upset him. I am simply shocked by this information and do not understand at all how to react if this woman gets pregnant. I already take the idea that my parents got divorced lightly, I'm not jealous in any way, I even like my mom's new boyfriend, but the idea that my dad will have a child with this woman really horrifies me. Am I an asshole?