Why did Pietro slap Tano's mother around

I could not fully understand as there was no dialog, but Pietro Favignana seemed to be affectionate with Tano's mother, then he suddenly became violent. After roughing her up he went outside and collected money off a group of soldiers who attacked her. When the house caught fire he went back and tried to revive her. Was she his wife/girlfriend and he was pimping her out, or was she a putana to begin with?