Ashamed boyfriend?

Me and my boyfriend are in a great relationship. But he is ashamed of being gay. And this really bothers me because I have no problem with it. I tried to hold his hand will walking on the Lake front and he was like "public stop". I saw other couples (who were straight) holding hands. I felt bad after. I don't do PDA like making out and stuff like that. I just wanted to hold in hand next to the beach because it was a beautiful day. I mean am I wrong, or is there a way I can make him see that there is nothing wrong with being gay.