Not German but I do encourage the users on this site to engage in their local kink community. As OP indicated he's interested in meetups I've found a couple events on Fetlife that the people in this thread may be interested in (a lot of people on here don't seem to be on Fetlife but it's the go to place for finding kink events).
Tafelrunde Mannheim, 68307 Mannheim 15 EUR PP
Tuesday, November 07, 2017 from 08:00
A very unique and historical location opens its doors for ladies and gents who love the very special game between Domination and Devotion and don't like to miss a culinary deligh!
Who are we?
We are a community that lives and love BDSM. we are always pleased to meet open-minded, curious and active people. We have one direction, manners and respect to each other. This is our Priority! For us BDSM is an attitude towards life! We laugh together, have fun and we benefit from each other. Refreshments are also served and included.
https://fetlife.com/events/594048
Restaurant Krauthof Beihinger Str. 27, 71642 Ludwigsburg
Saturday, November 11, 2017 · 7:00 PM
Auf diesem Stammtisch triffst du Gleichgesinnte zum Reden, Quatschen, Kennenlernen und zum Erfahrungsaustausch bei einem gemütlichen Beisammensein in lockerer Runde. Egal ob du ein „Alter Hase“ oder ein völliger Neuling bist – bei uns triffst du garantiert die richtigen Gesprächspartner!
Neue Besucher sind stets willkommen!
https://fetlife.com/events/603391