First dates can be excruciatingly awkward, especially if you have nothing to talk about. Considering it's a first date, chances are that you do not know one another, so what in the world do you talk about? You don't want to just talk about yourself, and eventually she will get sick of talking about herself (we hope so), so what do you converse about for the rest of the date?
For the average man, photos of attractive women, provocative or not is perhaps as essential as breathing and maybe healthy to keep the human race alive. But sometimes women tend to see this as a deliberate act of perversion rather than male appreciation. Remember, men are notorious for finding fertile women.