Love in Paradise.

A group of tourists go into the desert and their truck breaks down. Some go off for help leaving Victoria reading a book and day dreaming about wandering into the desert and being rescued by a sheikh who takes her to his palace in an oasis where she has sex with Princess Laeda. Meanwhile the other tourists return to the truck at different times and have sex. Then they go to look for Victoria, find the oasis and all have an orgy there by a swimming pool.