It Wasn't Me: Lying to save a relationship

I asked my guy friend how many different types of lies are there (in reference to a relationship) and he answered, rather quickly, "two." 

The lies you get away with and the lies you get caught telling.

Now why would someone voluntarily lie to his spouse is beyond me but he continued to explain that sometimes men have to lie in order to "save the relationship."

Below is a video by Shaggy titled "It Wasn't Me." The song is about a man (RikRok) who gets caught cheating by his girlfriend and goes to his friend (Shaggy) for advice. After he explains the story and the fact that he was caught "red-handed," Shaggy tells him that his best bet is to say that "it wasn't me."

In the end of the video, RikRok realizes how ridiculous he sounds telling his girlfriend that it wasn't him who was cheating even though she looked him in the face.

What I don't understand is why even attempt to lie in the first place? Granted we all make mistakes (some bigger than others) but when trying to fix those mistakes, wouldn't the truth be the first solution?

I began to attempt to break down the thought process of a man lying to save a relationship.

He cheats on his girlfriend so obviously he doesn't care about her,

Wrong.

Because when he gets caught cheating on his girlfriend instead of calling it quits he then tries to find a way to get her back so he obviously cares about her.

Maybe.

My guy friend ended his rant about lying when necessary with a simple, 

"Out of sight out of mind. What she doesn't know won't hurt her."

This could be true but in the end, when you really care about someone you shouldn't even put yourself in the situation that requires you to either tell the truth and hurt her or lie and spare her feelings.

The decision is yours.