I live in a 2 bed 2.5 bath town-home with my roommate and my girlfriend. Our rent is about $1425 total with utilities a month. the split is is in thirds where I pay for my GF's and my third and he pays 1 third ( each third is $475). now recently I had taken on my younger brother as his guardian, who is currently in high school and cant work more than weekends at any job around (at best he makes around $250 a month). My brother is living in what equates as our dining room, which was only used for storage until he moved in.
The current set up now is my roommate's rent with utilities has not changed equaling the same $475 he was paying before and I cover all extra apartment cost. but now he is demanding and even 4 way split between him, my girlfriend, my brother, and I essentially meaning he pays 365 and my GF and I paying 1070 plus whatever the extra utilities are.
overall I'm asking if he is fair in his demand of an even split? or should we keep the agreement as is? or is there another option that would equate to fair rent for all?