Putting race/religion aside, I think its a bad idea to get involved with anybody who is taken not to mention the fact that he is married not dating. If they have kids together I would reccomend leaving the situation altogether, dont do that to children, im a strong beleiver of two parent families. Its gonna hurt like hell but trust in god your future man is out there. But what ever decision you make, think about it very very carefully! I know you make the right choice.
:)