I had my girlfriend nair my back recently and I was surprised by the results. It was exceptionally smooth for like 4 days before I noticed it growing back in. My back hair is dark, but pretty sparse and thin. But I noticed about 5-7 days after being naired I started getting a lot of bacne, similar to how it was the first time I got my back "waxed" with the sugar wax shit. Is there any way to prevent this? Is it just in-grown hairs? How often should I nair? Thanks for any info.