I know. My husband and I lived in Saudi Arabia (Ras Tanura) for five years when he worked for ARAMCO. He worked at Juay'mah for three of those years.
My boss and thirty men in our department were all Saudis. I used to ask my boss and the other Saudis where I worked if they had multiple wives.
They all said two things:
1. Only the wealthiest men can AFFORD multiple/four wives. If he gives ONE wife a new house, he HAS to give the SAME thing to the other three.
2. When I asked them about multiple wives they ALL said the same thing: One wife is enough.
I can see how there could be jealousy problems, as jealous as a woman can get of another one in a chador.