Someone asked me the other day: Would you trust less a business partner who was cheating on his/her spouse?
Related question: Do you draw a hard line between someone's personal / bedroom conduct and their professional trustworthiness?
My answer to the first question: Yes, I would trust the person less, but I would not dismiss working with him/her out-of-hand. Second question: No, I draw a "soft line" between personal/professional.
I recognize that some people simply lack self-control when it comes to sex but not when it comes to anything else, or so they claim. Still, to me character is character, and if someone can be dishonest in a romantic setting, what else might she be dishonest about in a professional setting?
Culture matters. I was raised in America and Americans seem to care more about fidelity than most people.
In the end trust exists on a spectrum and one must weigh various factors. In a business relationship fidelity is not a deal breaker either way, just a factor among many. In a personal relationship I care more.
[Definitional note on cheating: There's the technical cheat (sleeping with someone other than your monogamous partner) and then there's what Chris Yeh eloquently described to me as "something that's technically allowed but really is just fucked up" -- like sleeping with your best friend's ex or sleeping around days after the end of a positive long-term relationship. In the end the semantics doesn't matter. It's about what a person's actions say about their underlying ethics, honesty, and self-discipline and whether bedroom actions speak to these attributes in non-bedroom environments.]
Bottom Line: I think less of a person who cheats on their partner, but in a professional context I do not distrust him/her altogether. I just trust them less.
Related Post: Trust and the Failed State