Sincerity can be quite an overplayed factor with cheating spouses since the cheater always thrives on the trust of the constant partner. The true spouse is kind of inclined into believing their partners recounts since this gives them both a feeling of comfort as much as it guarantees their security...
There is nothing as hard as getting to grasp that your spouse who you have trusted and regarded as your pal and lover has been cheating on you. The first thing to do is to accept the fact that it did occur and then become extremely observant of your other half's daily habits and behavior. This may be uncomfortable but it is necessary if you want to discover the truth...
