Most Helpful Girls
People can and do change, especially with time and maturity. I'd say if it hasn't happened again in the span of a decade, it's pretty safe to say they've learned their lesson.
Everyone make mistakes, and sometimes they grow, change and become more mature because of them. 10 years is a long time, and if they haven't cheated on any of their partners since then, I would have no problem giving them a chance.
Most Helpful Guys
I bet at least half the people here are bullshitting. Most would probably to continue to date that person. Telling someone you cheated in the past isn't a conversation that naturally comes up. It would probably be some time before they would find out.