Remember, silence is golden. At this point do not confront your partner.
Confrontations based on suspicions, intuition and distortions are unproductive.
You need facts. Confronting the other person with insufficient evidence is unproductive and counter-productive. Moreover, if you are certain that there is an affair, it is not always best to confront the person with the evidence. It might drive then directly and prematurely into the arms of the waiting paramour. What you must cultivate is self-control.