New men

So I am recently out of a 6 1/2 year relationship. I am very excited to be with a new man (physically). I have a question  pertaining to one of the men  I could potentially hook up with. one of these gentlemen likes a good slap across the face while having sex(so I am told by him) my question is do I have him tell me when he wants to be slapped or do I just do it? I assume how hard he likes to be hit is his preference?
Thanks :)