My SO has a son from a previous relationship. We have a daughter together (She is a newborn only 2 weeks old) His son lives with his mother where they have a dog and a cat. His son ended up getting a really bad rash and infection on his leg from the cat. My SO wants to being his son over tomorrow to hold our newborn which I strongly oppose of. I do not want my daughter to to get sick. I told my so to bring him when he his son doesn’t have an infection and rash and he got really mad. What should i do ? Am i wrong for trying to protect my newborn from any illnesses???