AITH for marrying a man who already had an obligation ?

I married a man 7 years ago who was paying for a home in where his mother and sis live in. This wasn’t a problem until we started having children of our own and his mom and sis started to be rude and disrespectful towards us.

During this time my husband continued to pay for most of the house payment. Despite me telling him several times that his sister needs to pay for most of the house payment as she lives there.

I am started to feel resentment towards him because I feel that his extended family is coming in first. We are getting help from my parents by living rent free in a back house because we can’t afford to buy our own since he has to pay the house in where his mom and sister live in.