There should be a bedding for a man. a bedding for his wife and the third one for the guest, and the fourth one is for the Satan.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لَهُ فِرَاشٌ لِلرَّجُلِ وَفِرَاشٌ لاِمْرَأَتِهِ وَالثَّالِثُ لِلضَّيْفِ وَالرَّابِعُ لِلشَّيْطَانِ