I know it's been a while since anyone has posted here, but I found this as I was navigating through this section of the forums and it struck me as interesting. As far as addressing our parents as "mom and dad" and the slightest notion that it would be considered "sinful", well, that's a new one for me. I've just never heard of anything like that before. I suppose (as I've seen in other posts) that it largely depends on culture or background, or maybe personal preference. The only way I can see it remotely being a "sin" is to use the terms around those who we know would be offended to be addressed as such (and I can't imagine anyone really being "offended" by such a trivial issue, but I guess some are). The words "mom" and "dad" are not swear words, it's just a revision of the English language when it comes to addressing our parents. It's perfectly acceptable today, and just because something is from today doesn't mean it's always wrong. Doesn't mean it's always right, either, but... I think everyone should know what I am getting at.
Anyway, everyone is different.