I vaguely remember this fanfiction where harry is being abused by the Durslys (I forget if it was sexual). Snape rescues Harry but as repayment makes harry into his sex slave. I believe it was noncon in the beginning or at least reluctance.
Also any fics with noncon or slutharry are always welcome! :-D
Also, writer voice is not speaking voice. If you try to follow the rules of grammar while writing your dialogue, you're more likely to end up with something that sounds stilted or forced.