My son turned 9 in January, and just about since then has become more concerned with being modest/having privacy, as well as not wanting to see DH or I naked...and since little sister (will be 7 in June) does everything he does, now she is more concerned, too. lol. So we mostly keep doors closed while going to the bathroom (previously open or closed didn't matter much), and we have robes available too. This coincides with DS really "getting" sex, and asking more questions, and talking about his own feelings, so it makes sense to me that it's evolving this way.
We have always had incidental nudity like going from shower to bedroom or bedroom to shower, or otherwise changing and never went to great pains to always be covered - but other than those times we always have some kind of clothes on, we don't hang out undressed (and didn't have the kids do it when they were little, either).
We coslept part time and full time with them in varying stages, up until the oldest was about 7 and the youngest 5, so they were no strangers to our bed - they slept with us pretty much until they were each 2-ish, then would start thenight in their own room but could join us whenever, and that lasted until 7/5....we would just move them, or go to one of their rooms if they were in our room and we were in the mood. I don't think we did it in front of them sleeping much past 6 months or so, it just felt weird to us.
So as far as sex goes, when DS busted in on us at like 1am when he was around 7, looked confused, turned around and walked out, turned around, came back in, and mumbled, "THAT was WEIRD." then turned around AGAIN and went back to his room and fell asleep immediately, we decided it was time to get a lock on our door. .
PS: I never got into the bathing with your baby thing, for some reason...neither kid, and I have a boy and a girl. I dunno why - I just always showered in the morning, and bathtime at night was playtime and then me scrubbing them, it never occurred to me to hop in because then I'd have to get myself dried off, etc and it just added another layer to manage at that point when I was just trying to get them both the heck to sleep. LOL. I am not mcuh a bath person anyway, so it wouldn't be particularly relaxing to me to have a small human roaming around a tub of water with me, potentially slippery from soap, and needing to be kept safe while we were both nekkid.
As far as when I'd personally think it was a "problem"?
Changing in front of kids: Never a problem, really - that's pretty utilitarian. I can see becoming more discreet about it as they get above 6, 7, 8...but not being rigidly modest.
Open door pee/poop policy: Never a problem, everybody poops after all. lol. Some of my best conversations with girlfriends occurred while one of us was on the toilet.
Bathing with kids: Would start to bother me as the kiddo got past the 5/6-ish mark.
Kids bathing together: Depends on the kids and their genders; mine are mixed gender and started getting a little weird pawing at each other when the oldest was 7, so we switched to separate baths at that point (we didn't shame them about it or even point out that part, really). Same sex siblings I'd be more comfy longer.
Sleeping with kids: Never creepy, it's sleep. We still do it on occasion but they mostly sleep all night now so nobody is wandering in anymore...we figured it would phase out that way anyway. Hell, I still nap in my mom's bed with her when I visit my parents, and I'll be 40 in September!
Having sex in front of kids: This is the one I'm most conservative about, and get creeped out thinking about with kids much above 3 or so. But I fully own that's my deal. And I wouldn't necessarily "report" anyone for it, but I would be weirded out in a big way thinking about a 5/6/7/8+ year old being in the same room/bed and hearing that, and either wondering WTF was happening or knowing and being grossed out....I would never be able to really enjoy myself...and yes, I know traditionally before people had separate bedrooms it happened all the time. But that's not the world I grew up in, so...not in my realm of experience at all.
Edited by The4OfUs - 4/10/13 at 8:55pm