Talking for everyone else

I’ve heard of pregnant women “eating for two”, but there’s also “talking for two [or more]”.  This takes a number of forms.

1. Talking for self, and for one’s children.  When I went back home for a visit after a 14-year gap, I met my eldest sister’s two daughters (aged six and four at the time) for the first time.  I thought I’d get to know them by asking them questions like “How old are you?” and “What hobbies do you have?”  For each question, my sister would step in and provide the answer.   Eventually, I had to say, “Do you mind?  I’m not so much interested in the answers as trying to break the ice.”  I can understand, to a certain extent, why my sister should’ve done that:  she might’ve been playing the protective mother role, in case the children were feeling a bit awed, but it ended up making me feel bad, telling off an elder which is not an acceptable thing in the Chinese culture (face and all that). 
2. Talking for self, and for one’s spouse.  In my experience so far, it’s more often the wife answering for the husband — so far, two wives I’ve come across.  In one case, the wife is the one who knows me longer, so I can sort of understand why she should be answering for the husband as he knows me less well.  In the second case, the wife is new to me, having married the chap some 20-odd years after I’d known him (he was a student of mine on my evening course).  Both husbands are in their 80s, which makes me feel that the wives (one 82, one 61) are almost treating the husbands as being too doddery to conduct a conversation in their own right.  (Which I find a bit insulting.)
3. Speaking for self, and everyone else present.  This form takes place when a guest of theirs comes to visit.  Again, trying to break the ice, I ask the guest things like where s/he lives/works, and like the mother example in (1) above, the hostess jumps in and speaks for the guest, even though the guest speaks good English and is a grown-up (with a university-age daughter).  (And actually, the hostess does not speak good English herself, which makes it even more insulting to the guest…)
4. Speaking for the speaker.  This is jumping in and finishing off the sentence for the speaker — practically always with the WRONG ending.  Feeling that I have to give him/her face, I can only employ one of the following: (i) say, “No,” and carry on with my sentence; (ii) go silent until they finish off the finishing off of my sentence, then carry on as if I hadn’t heard the butting in with the wrong version; (iii) get riled and say, “Please don’t finish off my sentence for me,” which was what I did one day for the first time — and felt a baddie for the rest of our meal together.  (It’s unfair that I should be made to feel the baddie…)