It's from the 70-80's timeframe.
Wealthy husband and wife travel to either India, Saudi Arabia or such. He ends up 'visiting' a brothel of sorts and gets an STD that ends up killing him while they are there. The wife is left there and ends up taking a lover. I remember sand, veils and horses where they are visiting..
That's all I remember.... sorry not much to go on. I don't remember the actors besides they were dressed nice (he in a light colored linen suit and maybe a hat).