Roommates Changing Rent Amount

[hoss4]

My question involves a roommate in the State of: Oregon

[hoss4]

My question involves a roommate in the State of: Oregon

My son and a couple decided to rent a 2 bdr townhome together, all 3 signed the lease and put up 1/3 of the deposit and 1/3 of the first months rent. The couple is now stating that he needs to pay half of the rent because he has his own room. This was never discussed before they moved into together, and the couple is not married and they wanted to share a bedroom. My question is my son should only be responsible for 1/3 of the rent, correct?

[Mr. Knowitall]

That is what is suggested by the agreement that they would each pay 1/3 of the deposit and 1/3 of the first month's rent. Beyond that, I don't know what their agreement was.