Hugs, SaraBravo I totally FYP! We started getting that crap as soon as dd was born (from friends, family, and even totally random strangers!). The assumption was that, since we had "one of each" we should now do the "responsible" thing and quit.
My parents had to deal with the same sort of thing (only worse!) because they had my eldest sister, then adopted my elder brother, then had 3 more girls (biological) before my younger (bio) brother was born. After my bro was born, so many people said horrible insensitive things like, "Well, you tried for so long, and now you finally have a boy! Even said those things where my adopted brother (who was about 13 or 14, so easily old enough to understand and be hurt by it) could hear them. It deeply hurt him, and I know it hurt my parents, too.
People are just so RUDE. And nosy. And just totally inappropriate (Toward the end of my pregnancy with dd, an employee at walmart--someone who I had seen several times before, and I tried to be polite and friendly because I always try to be polite and friendly to people, but she was definitely a stranger to me--asked me if I was dilated yet!
Anyway, with strangers, I use the Miss Manners approach. Slightly modified though....I've noticed that if you say "Why would you ask...." then that leaves the person (who is obviously obtuse and boorish to begin with!) an opening to continue. So instead of phrasing it as a question that they might choose to answer, I say "Forgive me for being so surprised. I'm not accustomed to having a stranger ask me such a personal question." Gets the same point across (hopefully) without giving them any room to make things worse.
Can't do that with friend and family though (although it's tempting, LOL!). I try to make sure that close friends and close family understand our beliefs(we do not use birth control, and are open to having a very large family, if God so blesses us), so hopefully they will respect that even if they don't agree or don't understand. If they just don't get it or can't seem to stop themselves from saying something, I try to diffuse it with a gentle, humourous approach. I told dh's gma that of course we wanted more children, because eventually they lose that "new baby smell" and then we'd have to get another one, LOL! I've also been known to say "Well, when you have children as sweet and smart and adorable as ours, why in the world would you want to stop?!" Of course, that only works if they are actually behaving at that moment, LOL!
As for the "don't you know what causes that?" question, there is truly nothing that irritates me more. How very inappropriate! When did it become acceptable to ask such things??
: Sometimes I use the Miss Manners approach and a really icy stare, but my favorite response to use is "Yes, we do. And obviously, we've gotten pretty good at it!"
For me, the main thing is having a response ready--any response, whether snarky, or gentle, or cooly polite. Just having a response in mind, so that I'm not left standing there with my mouth gaping, feeling angry and stupid.
We ought to start a thread for just such responses!
It would even make a great sticky, lol!