Please Help

my boyfriend doesn't understand how it is that I can we so wet and horny and yet unable to orgasm sometimes. I find if I am not in a location that is private and confidential I go like a flat battery unable to orgasm meanwhile he just loves outdoor public sex and we have been at it before and gave it up then he wanted to try it again and I just can't. what should I do or say?

he creeped out when I just shut down and said "can't feel a thing down there now and its uncomfortable, how about go back to our room" cuz I froze on him he is sour as shit.