Is it my business or right to be upset when his mother

Always asks for money? I'm 22 and he's 24, we barely make enough to pay our rent, food and etc but he always gives her $50 here, $40 two days later, $150 next week.. I'm going to school and working, I'm broke until I graduate!

I can't handle it and he expects me to not be upset when she uses him. I've been around this family for 6 years and I know what's she doing, emotional blackmailing him. "I'm your mother how could you not help me." He feels bad if she doesn't have any money but she's a nurse (RN)...she makes 2.5 times what we make, at least! We argue but he's so overwhelmed with me yelling at him and his mother yelling..I just walk away now and let him make the decision, usually he gives it to her but at times I walk away and hours late her tell me he didn't give it to her, he stood up to her. Either way we always talk about it and make up but the argument can get bad.

She spends her money on stupid things. She cries that she's hungry, we give her the money she asked for and she buys cigarettes right in front of me..what the hell! I gave you that to buy food and pay your water bill, not tobacco and a shopping spree at a department store (she hoards things from sale racks).

If he says no which he's done plenty of times, she shows up banging on our door (late at night), threatens our relationship, wakes the neighbors in our complex and or calls him 100's of times...she's insane so he just gives it to her to shut her up.

I've been told by several people I have no right to tell him what he can and can't do. "It's his mom you have no right." I want to spend the rest of my life with him, have children but with his mother depending on us so much, how can I have children? I hope one day she realizes but if not I guess I have to move on.