(c) 2010 Ms. Huis Herself at musenmutter.blogspot.com
In economics, there's a concept called "cost-benefit analysis." Basically, it compares how much something's going to cost, with the potential benefits/return from said cost.
In parenting, I think sometimes it's more of a "joy-hassle analysis*." How much joy/pleasure are your offspring going to get out of something vs. how much of a hassle is it for you. Getting to use a crazy straw? High joy/low hassle. Painting? Might be high joy, but it's also high hassle. Bringing your non-napped, overtired, teething small fry to a fancy restaurant? Yeah, that's just a lose-lose, low joy/high hassle situation, most likely.
And all this is just a fancy way of saying we're letting the girls wear their swimsuits in the bathtub tonight.
*My idea, all mine, so poopyheads, hands-off. Nice friends, go ahead and use. :)