Does the issue of "al-hamw al-mawt" (the in-law is death) include everyone, both husbands and wives?

The Hadith "Al-hamw is death" means that the husband's relatives—those who are not mahram such as fathers and sons—are more feared for causing fitna (temptation/strife) and evil than others, especially the brother, nephew, paternal uncle, and paternal uncle's son, and similar individuals who are not mahram, due to people's leniency in being alone with them. Being alone with the wife's sister or her female relatives is forbidden and a fitna. Therefore, one must avoid being lenient in being alone with them or looking at them, because women are the greatest fitna for men.