During my teen years my parents yelled at each other every evening. I spent time in my bedroom studying to avoid it. You would think they hated each other. They will be married 65 years tomorrow. They still yell at each other. Guess they are well mated - they must enjoy it on some level.
Sometimes it takes strong feelings of intimacy, trust and comfort with another before one can express intense emotions like anger - as long as they don’t interpret the yelling as personal attacks on themselves, it’s probably cathartic and even “enjoyable” for your parents - sure hasn’t hurt after sixty-five years - great achievement......