I say: “My in-laws”. That is the way I’ve always heard the term being used to describe that relaytion.
- Is this accurate strictly speaking?
- If not, then when does the popular will of a billion English-speakers change make it so?
As there is no direct marital link to yourself, there aren’t your in-laws. They should be described as your daughter’s in-laws, as they are her husband’s parents.
I believe the correct term is “those cheap bastards who wouldn’t even pay for the wedding reception” 
In most families, there is a choice of various terms of opprobrium, but I find just calling them late to dinner is enough.
Of course if you lived in a Spanish-speaking country it would be easy:
Consuegros
just my .2 cents.
XicanoreX
Here is just one of millions of references to using the term “in-laws” to refer to the other set of parents:
[Robert Ebert on “Father of the Bride”]
The best moments in the movie are not, however, the passages of obvious comedy (I didn’t much go for the extended set-piece that involved Martin visiting his in-laws’ bathroom and ending up in the swimming pool). This is a movie with heart…
Source: http://www.suntimes.com/ebert/ebert_reviews/1991/12/686197.html
Is Roger Ebert wrong? Or is he, like the rest of us, using this term in an equally legitimate way?
You could also go with “The psychotic bitch and her lazy good-for-nothing husband” or perhaps “Those people”.
Out-laws? :D:D
The generational flip-side, your mother’s husband’s children would be your step-siblings. So maybe some sort of step-something term.
How 'bout co-parents?
[hijack]
One of the definitions of “sister-in-law” is “the wife of the brother of one’s husband or wife”. When I refer to my wife’s brother and his wife, I say “my brother-in-law and sister-in-law”. Then if I mention their kids, I get looks the comments like, “Your wife’s brother and sister got married? Ewwww!”
[/hijack]
I’ve always thought “limpdick” and “skank-whore” had a nice snap to it
I don’t think the spouses of your husband’s (or wife’s) siblings are technically related to you. (At least, that’s what I always thought)
Your wife’s brother is your brother-in-law; his wife is just your brother-in-law’s wife. You can call her your “sister-in-law”, though, for clarity in conversation.
Example: I have three sisters. We are all married. Our husbands are not really related to each other, other than the fact that they are all married to sisters. They do call each other their “brother-in-law”, but IIRC, they are’t technically in-laws.
(I could be wrong…)
sis•ter-in-law pron: (sis’tur-in-lô"), —n., —pl. sis•ters-in-law.
- the sister of one’s husband or wife.
- the wife of one’s brother.
3. the wife of the brother of one’s husband or wife.
Definition 3 is the one I was referring to. I’ve seen it in many dictionaries.
It makes sense in that the niblings of one spouse are the niblings of the other. “Aunt Clara and Uncle-in-law John” seems rather awkward.
I’d say in-laws is accurate, at least according to the dictionary definition of the word:
Of course, that’s kind of playing loose with the term…
There’s a word in Yiddish as well as Spanish:
makhatunem (plural) or makhatunista (adjective, I think)
There aint a word in English.
If you have a cooperative relationship with your daughter’s in-laws, I’d say call them your co-parents-in-law. Later, you may be able to refer to them as co-grandparents, or the other grandparents. This is how my mother referred to my brother’s in-laws until they became “those people”.
Well, okay. It does make more sense.
(I did say I might be wrong.)
::: off to find the dictionary and keep it by the computer :::
I would hope you would just call them ‘Friends’
Well, what are their names?
If you want to do it by describing the relationship, well, we all know exactly who you are talking about because you described them perfectly - as your son-in-law’s parents.
Tibs