Dexterish

The Killer Instinct books, which are two, Killer Instinct and Killer Within are a bit like the Dexter books.  I read them a million years ago, but I remember really liking them.  I have never seen the show though.   In this case the person with murderous instincts is a teen female with a complicated family.  The thing I found really icky about these was the sex.  I mean, I am totally not a prude.  I really am not.  And the language didn't bother me and I am not the kind of person who thinks that violence is fine but any kissy-lovey stuff is wrong, but the graphic nature of the sex seemed...I don't know...misplaced?  It just didn't seem to me that someone of this age, even someone with serial killer potential, would be that versed in the terminology and so forth!  It just seemed weird.