Can't have everything. It'd be better if I could post in Cyrillic here but oh well.
Well, [to aggravate you further with the russian grammar] this emphatic clause "yob tvoyu mat' " is an interesting exception : it remains in singular, even when the addressees, like, say, "tovarishchi", are plural. Normal rules would require getting it in plural, too: "yob vashikh materej/matushek" would be needed, but is never used - just the clause in its regular singular, although singular pronoun 2nd person pronoun "tvoyu" could be substituted by 2nd person plural/polite singular "vashu". But "mother" ALWAYS remains in singular.