Am I selling myself short?

A year ago I met someone who blew mind mind. We hit it off immediately and still have a great time when we are hanging. I know everyone says this but I genuinely mean it when I say that he is smart, sensitive, funny, an amazing musician with a great taste in music.. oh, and our love life is pretty awesome too. The only problem is when I met him he had just (and I mean in the same week, just) broken up with a woman he was with for 7 years. I get that the feelings don't just dissolve after a relationship that long. I know that because he still may have feelings for her that he doesn't mean it when he tells me he loves me. But it took almost a year for him to be able to tell the ex he wants to remain friends with that he was even seeing someone, let alone living with me. It wouldn't have been quite so bad if he had mentioned me to at least his friends/family but seeing as they are all so close with the ex, he felt it best to keep it hush hush. Now that he has just "come clean" he almost seems uncomfortable when I express excitement about finally meeting his sister. Maybe I am just to inside my head and need to enjoy the ride but I don't want to invest any more time in this if he is not being honest with me. Should I stay or should I go now?