one's son and his wife; son and daughter-in-law
Refers to the married couple consisting of one's son and his wife. Commonly used when talking about family relationships.
I heard that my son and his wife are buying a house next month.
I went out to eat with my son and his wife.
Refers to one's daughter and her husband, while 息子夫婦 refers to one's son and his wife.
Compound of 息子 (son) and 夫婦 (married couple).