Slut shaming only happens if you participate in sexual activity, or if you enjoy/have lots of sex. Reading about sex is a completely different thing, moreover, you are not even a slut so this cannot apply, unless you do enjoy lots of intercourse with others and people do call you a slut.
You are probably frowned upon on for enjoying smut, which could be equivalent to watching porn, or doing sexy RP chat/costume. Some people find activities like yours and others I've mentioned weird and different, but as long as you don't harm anyone, reading smut is your choice, and is not a bad thing.