Waiting for them to slip up is inevitable unless they are some superhero in having an affair. You'll become paranoid because they talked about a certain memory with you that you have no recollection of. It could be a movie that they said that you watched together, but you know for a fact that you haven't seen that movie. You'll become paranoid as to why they always have to go over to their friend's house on a weekend and why they can never come to yours instead. And of course, the person who is cheating on you will become paranoid simply because they're doing it. And if they're doing it to you, why can't you be doing it to them?
