What do we do with 2 overwhelming sisters?

My fiance and I have 2 very pushey sisters.

His acts as if there shagging, by demanding his time constantly and is jelouse if he turns her down to do something with me.she also spends to much time dwelling about there childhood and brings him down about it. not to mention that she mothers him! yuck! she is his younger sister, to me she seems to needy. and always want to be at the center of attn.

My sister always calls to ask for money, always needs something, never looks for me unless she needs something. and disapproves of my fiance and is always trying to make me pick here over him, for instance inviting me and my son over for dinner and not him. she bad mouths him to my family and uses him as well when she needs something. when we got ingaged she asked if my ring was fake insted of tell me it was nice.

he thinks we need to leave the state to escape family i think we need to find a middle ground with theses two? can anyone help?

we already use the word no, it makes it worse.