Talking closely in someone’s face is never acceptable, even when you’re metaphorically close to them. Regardless of whether you brush your teeth more than twice a day, the smell of breath is always just that: breath–and no one wants it wafting closely to their visage, especially a lady. Plus, “men” who talk closely are notorious for not actually having anything worthwhile to say; they just want to assert themselves and this is the best way they know how.
If you have a secret or something dirty to say, you can whisper it into her ear. This is far sexier and more preferable to getting up in her face so that she can see that faintly forming whitehead underneath your nose. Think of it this way, do you like to look at women in HD? No, you don’t. And if you didn’t already know the answer to that question, it’s because women have the good sense to not reveal that they’re full-on Monets to you by not coming within .03 inches of your face (unless, of course, you’re eating them out–which you’re probably not).