do you tip at resturants?

1st of all, you should all be Jealous that he actually ate "Authentic German Food" !!!!! IT's YUMMY ! I eat it often cause, I grew up with it. And can cook it too !
Now, considering your going to a "German" restaurant u would expect to tip a bit better, Just cause it's a so called Theme restaurant. Say 20 %.
That said, if I ever went to ANY restaurant and the waiter SAID, I didnt tip enough AND ran out to the parking lot. I'D NEVER go back until the owner /chef, whatever made it up to me.

Just My .02