Would you be upset in the same business situation?

So here's the deal ... I mentioned the opening of a small business in the near future, after having more money saved for my boyfriend who has a full time job , but not long ago and has no money saved. How nice that he went and told his sister and spoke by phone with his father and his father offered to help start the business with $ 5000. But here's the deal ... He said his father said earnings are divided 50/50 between him and his sister. They do not have the first clue how to start a business and as it was my idea first, I spent hours researching , get quotes and all the information needed to start . I am very upset about the whole thing now and I told my boyfriend that the 50/50 without being included was BS! I am the one who can put more time and energy into the business because it will keep the job you have and your sister does not speak English very well and stays home with 3 children. She has little or no time to invest every day soooooo just because his father is lending the money (I've never asked in the first ) has the right to tell his son and daughter 50/50 and I have 0 and put more hours? Yes, so no matter how much we complain about it ... my boyfriend says ... " Well, that's what my dad says ." So I'm about to say that he, his sister and his dad is the goal where the sun does not shine without my help.

Although his father is "loaning " the money that his father is the president, it will not work in the business and would be only "temporary" investors.

I do not think I'm wrong for being upset ... What is your opinion and would be in the same situation?