I would have left him after he said you would always be second best to his family. There is so much embedded in that one sentence.
It says "Don't expect anything of me, don't expect commitment, I will decide the level of commitment in our relationship and not you, and you are second best to the people I love so don't interfere with that hierarchy" .
Apart from the fact that you are not his first priority, HE is taking all the decision-making power for himself. Why does he get to do that? Don't you have a say? Shouldn't you both be coming to a mutual decision about the seriousness of your relationship? It's so bloody arrogant and entitled of a man to say this to a woman.
I am not saying it is wrong for a man to be committed to his own family btw. Not at all. That is generally a good thing. It's the fact that he is so arrogant and dismissive of your feelings and that he is setting out the terms of your relationship without your input. An assumption that you will put up.and shut up. Ugh.
Also there is no humimity in that sentence either. Not a hint of "I wonder if she happy with me?" "What can I do to win her affection?" "Will she put me before everyone else?" He is so bloody cocksure that you will accept his terms and conditions and thinks you are lucky to have him!
At least he was honest I suppose. But please, please don't settle for being treated this way.
Fine if you are going out casually, but once you are in a committed relationship, I think you should be entitled to believe that you will come first with your partner. You deserve better. Would you want any future dc to be subjected to this hierarchy of love? Or would they immediately become family leaving you out in the cold?
Run for the hills! Don't allow yourself to be used in this way!