My boyfriend's child's mother always wants to do things with the three of them. Am i wrong to be upset?

You are so right in assuming that the mother of his child is very much infatuated by him. It is very commendable that he has taken responsibility for his daughter. He really needs to get a court order to give him the right to see his child. If he doesn't, it sounds like she is the type person who would eventually deny him visiting privileges.