Husband likes PDA but I am not comfortable with it. What should I do?

My husband loved public display of affection. He likes kissing me in public. I feel uncomfortable kissing him among strangers. I feel its just a show off. I let him hold my hands, but feel awkward when he suddenly stops and kisses me. Sometimes, when he is about to kiss him, I quickly give a peck on his cheek just to avoid the real (lip) kiss. He gets annoyed when I do that. I am a very modest gal and think that such things should be done in our own private space. It looks very immature to me. Moreover, the culture I come from doesnt appreciate PDAs too much, but as we r in US, he thinks its ok not to think about culture as no one cares wat we r doing. Should I just give in to his demands or let him know how I feel about all this.