can you have sex with someone who has herpes and not catch it?

Is it possible yes but there is always a chance there is never a guarantee.

Here are the Female to Male transmission rates

If you have 100 couples where the female has HSV 2 but not the male (these figures are over a year) the odds of female to male transmission are if you do nothing other than avoid sex during an outbreak 4 men out of a 100 will get herpes in a year or 4% If you do go on a suppressive therapy then it drops to 2 men out of a 100 in a year or 2% and if you use suppressive and a condom the chances are 1 man out of a 100 will get herpes in one year or 1%.

This is over the course of a yr and based on sex 2 times a week.