So apparently Damon “lets himself fall in Liebe with his brother’s girlfriends” 

Well, I'm sorry but I really think Damon had a thing for his brother's girlfriends. He can not fall in love with someone who isn't related with his brother. Of course love is something that happens without think but it seems Damon can only fall in love with stefan's girlfriends jajajajajaj

Ermno. Damon never had any intention of falling In love with elena, and she certainly never planned on falling in love with him. She fell in love with him on her accord, And who can blame her really? She was never going to be truly happy with Stefan. He's a born manipulator. Anyone with eyes can see it.