Falling of the Facade

Andromeda Tonks was raised in the noble and the most antient house of Black. She was taught to loathe non magical or impure people. Most importantly, she was taught to put up a cool facade even in the most dire of times. But her facade is crumbling. And why, for Merlin's sake is she fraternizing with Tonks, the mudblood Hufflepuff filth? She isn't even confounded!