Case in point Acts 15:36-41 is when Paul decided go on a second missionary journey and Barnabas wanted to take John Mark. Paul didn't want to take him again because he had withdrawn from them and didn't finish the earlier work. Paul didn't want to set himself up for that potential disappointment of John Mark leaving again. Paul and Barnabas had a discussion and they didn't agree about this. Barnabas and John Mark separated from Paul and went somewhere else. Was Paul in the right to not have him come with him? Yes. Was Barnabas right to part from Paul and take John Mark with him? Yes. Both men were correct a separation was needed, both men recognized it and went on about their way. Sometimes loving your brother may mean a separation for the better of all. If Paul practiced what he preached, he forgave John Mark for leaving him earlier. Do you think Paul forgave him? Yes. Does that mean things had to go back to the way they were? No. Paul in this case forgave, but did not forget. They needed to separate, cut down on the drama and continue on with God's work. God's work is the whole point after all.
This example from Paul and Barnabas is enough to convince me that even after someone has forgiven another they may not be able interact as before the offense.