As my lawyer said in jest, "if OM bothers you, we can always call Guido, but then we would be breaking the law".
Seriously Ral, I think only you can answer the question about what to do if you find out there is OM. We can only give our opinions on what we would or did do in a similar situation. It is up to you to define your own boundaries.
As for myself, I never had proof that she was sleeping with OMs (except for contracting genital herpes), however, she insisted upon dating and I drew a boundary to uphold my dignity - she could not live under the same roof as me if she was dating other men.
