I can't think of one that refers to living together, except for one that isn't really a saying - just a commonly-made observation that owners grow to look like their dogs. But there is a saying about people with similar characteristics tending to spend time with each other:
'Birds of a feather [=having similar plumage] flock together.'
PS I know very little Dutch, but I assume "vlooien" refers to faults. You may like to know (or know already ) the cognate English word "flaws" (which doesn't look very similar, but sounds it: /flɔ:z/).