I was just wondering can serious problems arise if a white guy has sex with an Arab girl and I am talking like in the US?

Like what kind of "problem"?

Well in the US if race doesn't bother you then don't let it. There are so many people who will try to put you to shame for being with an Arab girl because you're white. If you like her and want to have sex then NOTHING should stop you, it's your life with your choices. Sure you might be looked at differently but if you don't mind and she doesn't mind then who the hell cares what people think anyways.

No problem that is ur wish if you both has no objection to do sex

Problems? You might discover she is human like the rest of us.　If you let race or ethnicity dictate your relationships I feel sorry for you.