A boy's relationship with a step-parent can be very confusing in the best of cases, when the boy has good support and knows he can talk about how he feels. But if the boy has been abused then it can all become much more difficult, since in many cases he just doesn't know what is expected of him, how to relate to this new person, or how to handle the relationship the new parents has with his natural parent. If that's what's going on in childhood, then a lot of that ambivalence will show up when the boy becomes an adult.
So maybe the message you are sending isn't so much "I don't want to talk to you" as it is "I don't know what to make of our relationship".
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)