If he has made you a part of his life and his childs life it is definitely your place. Him introducing you to his daughter is a HUGE step in saying he is serious. In the beginning of the relationship you have to let it be known otherwise you are enabling him to do whatever he wants. He's not giving you the respect you deserve and it sounds like you are giving him way too much respect. Not sure why this issue hits me hard but most of the time its hard to find women who are understanding of the situation.. I guess what gets me is you understand and he is taking advantage of that.