You cannot get sponsored by your boyfriend. If he is in company accommodation, your neighbors will know your marital status. It only takes one disgruntled person to turn you in to the police. Arrest, jail and deportation for adultery may follow.
I sit likely to happen? It may depend on the employer (google qatar airways), or if you are a mixed race (non-white westerners).

You need to educate yourself on the laws here and the probabilities/possibilities are if you do not marry.