Neither.
My ex did both.
At the time I thought maybe he was mental, but now I see that many/most men routinely lie to gain advantage of women or evade responsibility for their errors.

But I also noticed women protect themselves from their more powerful, dangerous male lovers and mates, by being flattering and evasive, telling men versions of events that more likely won't provoke jealous revenge.

The very concept is “cheating” is assuming one is lying. They’re the same. Truthfulness is trust. If I love someone and they love me I couldn’t care less what else they do with their genitalia. If my partner tries to hide another from me, I know the trust is gone and that betrayal is what is so hurtful. Respect and trust me enough to tell the truth.

I think that a majority of the population stretches the truth a tad bit and so fibbing about trivial things wouldn't bother me - cheating however, is a completely different matter and I would have to walk away.

I absolutely love being brutally honest.
Lying damages trust, and credibility,
I also considered it to be cowardly.

Cheating is having a unfair advantage over your oponant.