It all depends on your definition of trust, cheating and lies.
For example, I've always been here for my fiancée. She was very ill (severe postpartum psychosis) during 2+ years, and many people told me they were amazed that I would still stay with her. That's the most basic definition of trust to me : she needed me, so I stayed and she knew she could count on me, no questions asked.
On the other hand, I occasionally (twice in 6 years) spent the night with attractive girls that I'll never see again.
I fail to see how it means I cheat on my family, or how it should affect their trust in any way.
I'll always do my best to be there for them.
And it would be moronic to let those 2 nights destroy our years-long relationship, that, even with a long illness, has been f**in great.
Fun fact : My gf once confessed that she cheated on me. I was relieved, and told her "me too". We acknowledged that it can happen, that it's not so big a deal, and we should try to keep extramarital affairs to a minimum.
Best regards from a sociopathic piece of shit.