I lived in Saudi Arabia as a kid from 1976 to 1979 while my father worked for Lockheed and there were other international companies that provided housing and there were other people with kids there and we had xmas trees in our homes there; while we were there most expatriats mixed socially and didn't mix much with the arab community unless you went out to the suk (market). But xmas was celebrated there among the Americans and others from other parts of the world who were living there at that time.
LRG