for me I don't know about Qatar Airways so maybe some one else from there can answer your question.
From my experience I know some Crew ( well my Mates ) who fly for Etihad and Emirates and are married but they never mentioed that at all during the interview or even flying together. they all live together and happy.
so I think most of the Gulf Airlines are the same !!
Hope you didn't hold your big sign and in capital letters ( I'M MARRIED ) during the open day or assessment .... haha. just keep it to your self love , they wouldn't check with yout Goverment. or Embassy in Arabia.
Cheers