Should I choose “Mr. Married Guy“or A guy whose not yet over his Ex

I’m wondering,
For guy number 1, I know being close to a married guy is a No,No and I already talked to him about the boundaries that we should set though it’s hard but I need to do it to respect his marriage.

Guy number 2, On the other hand, should I take the risk of being close to a guy whose not yet over his ex?