That is up to you. If you have a good relationship w/them and you enjoy being around them, then go. If they should question you about the situation, you don't have to lie, be honest w/them. It's not your job to cover the affair up, if you are asked about it.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
