Ahh yes, the ol' 'Madonna-Whore Complex'. Coined by the founder of psychoanalysis himself, Sigmund Freud.
He defined this condition as 'the inability to maintain sexual arousal within a committed, loving relationship' and that it 'is said to develop in men who see women as either saintly Madonnas or debased prostitutes.' It compartmentalises women into two simple categories - the pure and the tainted.
Turns out, many men are happy to make sweet, sweet love to their wives, but would be horrified to share with them their kinky side. So, they go looking for it somewhere else - e.g. a brothel.
