I think when it comes to married/attached men, you need to keep your distance. Yes, they may be in a strong committed relationship blah blah blah but I've seen/known many married men flirting with young, single women ... personally, it makes me sick. The temptation is there, and it can only take a moment to change inncent flirting into something more. If loose women throw themselves at the married men, they are usually met with very little resistance ... IMO.
As for flirting, there are boudaries, can you not find a single/unmarried/untaken man to flirt with out of the millions out there?