Every woman's skin is different. Some broads couldn't handle a cold butterknife across their leg without getting bumps, while others can handle a slingblade to the snatch and not notice a change in the junk.
The only thing you can do is make sure you are taking all the steps necessary to avoid bumps.
#1. Your shaving technique.
#2. The type of razor you are using.
#3. Your skin's natural reaction. (Can't do much about this)
#4. Water - Cold or Hot. Depends on the woman.
#5. Never use soap - Use shaving gel or creams.
#6. Never "dry shave" or "wet shave" without using any of the above mentioned.
#7. How often you shave, and how much of a tolerence you have to it. Your first 5-10 times you will get bumps. But your skin will get used to it eventually.
There's more, but those are the basics.
P.S. The best way to avoid razor burn is to be careful you don't run the razor over the same spot too many times. This is why a triple / sharp blades are so much better. Trimming is ok, but nothing sucks ass more than going down on a girl and having to "spread the forest" if you catch my drift...
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