In the relastionship matter infidelity is a common issues of thier society today, anger, insecurity ,dishonestly and unrealistic expectation are he root of some reason why men cheated to women as they partner ,regarding to their feeling and particular moment fails to understand that expectation are not met and seeks external fulfilment to one person ..definitly anger to their partner are the most common  reason occure infidelity caused he want to hurt her/him in such cases ,sometimes it seems to know that man does not keep the lie or secret about the cheating because he wants to his partner about it,