TextBlock: make it wrap if doesnt fit and but Stretch on long word

Is it possible to make a textblock wrap on each new word,
BUT if the word is too big to fit, I want the textblock to stretch.
Like this:

The first two words fit OK, the third word automatically wrapped and the fourth word caused the block to stretch.

Setting a width on the block forces the text wrap but unfortunately it breaks up words.

I suggest that you implement that yourself by properly replacing spaces with newlines.