hesitating
When someone is hesitant, they are not sure whether they should do something. They might be hesitant because they are not sure whether it is the right thing to do, or they might be hesitant because they are not sure how the other person will react.
He was hesitant to answer the question, because he wasn't sure how the other person would react.
She was hesitant to answer the question, because she was not sure whether it was the right thing to do.