Impossumable!

If you have read the Purple is a Fruit blog at all, you know that a really fun game to play with kids is to hang them upside down by their feet and yell "POSSSUUMM!". The key thing to remember is that there are times when you shouldn't do it. Immediately after they suck down a belly full of milk, and you have them suspended over your face, and your wife is feeding the other baby, and so engrossed in a book that she doesn't even hear your cries for help... that's pretty much the situation described by the term: Impossumable.