Sentence:  the collection of people who would gather in either of the two houses for Christmas and Thanksgiving, and sometimes again in summer. This collection involved former mothers-in-law, former husbands, ex-wives of former husbands, and doddering uncles from distant marriages, as well as, of course, the various and sundry children and dogs (dogs-in-law as one family member calls them) of the now recombined families. In the process, I believe, we were responsible for the creation of a new American family relative—the wife-in-law, or the <WSD>husband-in-law</WSD>. 
Meaning of the word marked with <WSD> tags:  Another husband of one's wife. Typically used in cases of divorce and subsequent remarriage.