Its strange how a single moment or a few words said in anger or hurt can change your entire view of a person. Once that moment happens there is no turning back.
If you lie to someone then you are forever viewed as the person that lied. Same goes if you are caught cheating. You are forever seen as the cheater and no matter what there is nothing you can do to change it.
Even more so, that person will always resent you for it. It will always be there between you....assuming, of course, that you have been 'forgiven'.
It will come up.
Eventually you start to lose yourself trying to prove to that person that you are worth trusting.
There is no winning in that because one day you'll realize that your efforts are to no avail and there is nothing left. The day will come where you know that love isn't enough.