http://www.novinite.com/articles/182952/Romania+is+Planning+to+Ban+Gay+Marriage+by+ReferendumRomania plans to hold a referendum sometime in the Autumn constitutionally banning gay marriage. Of the Eastern European countries accepted into the EU only Estonia and Slovenia (where a gay marriage ban failed due to an inability to reach quorum) do not have such a ban in place.
Notably this split anti-corruption party the Save Romania Union, with its members voting against the ban causing the leader Nicusor Dan (who had a few favourable media write-ups a while back) to leave.