Textblock should expand surrounding elements. How?

Question

Hi there,

is it possible to get a TextBlock to expand surrounding elements? Similar like a cell in HTML would become wider depending on how much text is in there.
What I wanna do is some kind of a Tooltipp which contains a few single lines of text. Those single lines of text (made of TextBlocks) should not wrap which is possible with the "NoWrap" attribute. That is the first thing. But can I get those lines to expand a surrounding element like a grid, stack panel etc.? The Textblocks are getting trimmed which I do not want.
The tooltipp looks like this:

-----------------------
|.....Name: XXX........|
|.....Email: XXXX.......|
|------------------------|

If  "Name" contains more characters the whole box should then become wider.

Thanks a lot!!