They are married of course. Cohabitation laws are very strict here. If you live together you have to be married, otherwise is strictly against the law. In some Gulf countries the punishment is time in an un-air conditioned jail (no room service either), lashings, and in case the perpetrator is an expat, eventual deportation. These laws are also present in Qatar, but are not implemented as harshly, assuming the culprit is non-Muslim and a Westerner. But, common sense should prevail along with respect for the culture and religion. The old rule and cliché ‘when in Rome … ‘ should be followed.
The Arab culture has a deep respect for the institutions of marriage and family. Here, married couples and families enjoy many privileges and garner great respect. So if you are thinking of moving to Doha and are married, better yet with kids, come on over!