The entitlement of dual citizenship rests on the countries he wants to claim citizenships from. The USA allows dual citizenships, though I'm not sure about Germany, Poland or France. You might want to ring their respective embassies or go to their websites and do a search.

Now, if you guys are married, you can go about it 2 ways.

One is for him to go back to the US and apply for an EEA Family Permit in the New York office of the UK Embassy, which I did. It takes them 5 business days to process the application,no red tape whatsoever. In a little over a week, he could be back in the UK, and can work immediately, and the only proof he needs to show is the EEA Family Permit in his passport.

Other way is for him to process his second citizenship (and this may take ages), but once he is granted that second citizenship and holds a passport, then he can come to Europe anytime without restrictions and work permits.

 

I understand your concern on not wanting to get married, just to make things easier regarding visas and permits. YOu should get married because you WANT to, not because you HAVE to. So both of you are doing good.

Having said that, you might want to do some research about getting an EEA Family Permit or something similar, but for unmarried partners / co-habiting partners visa (or permit). It has been talked about in the forums but unfortunately, I know very little about this. Hopefully EasyExpat will be able to answer this one for you.

 

Concerning the EEA Family Permit being applied to Unmarried Partners, I can tell you now that no British Embassy will accept co-habitation, for however many years, unless you have a "very good" reason not to marry. And there is only one "very good" reason in their books - if it is legally impossible for you to wed (ie. if you are a same-sex partnership in a country where same-sex marriage is not accepted by law). My lawyer told me that the Embassies have a very loose definition of the term spouse - this is not true. The British Embassy in Paris told us not to bother handing our forms in if we weren't married, and likewise all the Embassies in the US. The Home Office website lays down the rules very clearly - for them spouse means wife/husband and please don't let a lawyer tell you otherwise.