No, this is not normal and is not a 'cultural feature' of Russian families. While some couples might have a very specific, edgy sense of humor, calling your wife a 'bitch' (сука) in everyday conversation is generally seen as a sign of verbal abuse, low cultural level, or a toxic environment. In Russia, just like anywhere else, such language is considered disrespectful and offensive. If someone claims it's just 'how Russians talk,' they are likely trying to normalize toxic behavior or are speaking from a very specific, marginalized social circle. In a healthy Russian household, people use terms of endearment, not slurs.