Op look at it this way. If you hated your dh and wanted to to the worst thing to him that would cause him the most pain, this affair is it.
This. The poor man. 
And not just your husband, either. Your kids. If you hated them and wanted to inflict the most crippling insecurity, doubt, self-hatred and inability to trust in love and relationships themselves as they mature, then discovering as teenagers that their mother was cheating for 6 years (at that age, it's from young childhood to what they see as almost grownup) would do it. It will devastate them if they ever find out, and I'm sorry, but the reality is at that age they will be such black and white thinkers they will never truly forgive you or trust you again. In fact, they may even refuse to see you, at least for months, perhaps years, possibly ever. You will be planting emotional landmines under their entire childhoods, and I have to believe that you would never, ever intend that. You started an affair with young kids, with an ex so presumably trying to recapture the thrill and carefree nature of life pre-parental-treadmill, and now six years have passed and their lives as they've always known them were based on lies. Please, please end this before they ever learn as much. Please. I'm genuinely wincing to think of the harm this could do them. They're your kids, and you need to either leave and spend a bit of time alone before meeting someone new, or try to make a genuine and faithful go of it with their father.
I so, so hope neither he nor they ever learn of the past six years and the best way to ensure it is to end the affair dead. If the affair is uncovered, sooner or later so will its length. How can you risk that for your kids?
I'm not saying this to be hurtful or because I think life is simple. I understand how people drift into things and the years pass. I'm not being judgemental. I'm just suggesting that you may never have truly stepped back to look at what was slowly evolving, and choices you were making on an ad hoc basis, and the true scale of potential consequences may just not have dawned on you, as the affair began with young dependant children in the picture - not vulnerable young adults, with their entire life experience centred on the childhood they think they lived. Please, please think about what it would do to them if you don't end this, and they find out. Who do you love more - the other man, or your kids?