I concur with those who advise caution based on my experience. I was in a brief dalliance with an old boyfriend (from freshman year of college) that started shortly after I had ended my 16 year relationship with ex (we had a domestic partnership and I terminated powers of attorney, etc.) and it became a HUGE issue ego-wise for ex, then became part of the law suit. My ex convinced the first judge of a pack of lies (that I had been sleeping with the former boyfriend the summer before I left, etc.) and I had to move heaven and earth to prove my case (the guardian and second judge looked at the actual facts rather than ex's groundless allegations and it became a non-issue, but it took a lot of work (and money) to make that true)...
Moreover, I was not ready for a relationship so soon, and those few months ended up doing more emotional damage to me when my college boyfriend turned out to be a schmuck (again, he had been a schmuck in college!)....there were signs early on but I was not in a position to see them due to the emotional stuff swirling at the time of my breakup and the need to feel loved and "stable" on some level. I think my trust in men was hurt more by the old boyfriend relationship when I was so raw and trusted (again) so easily...
I recognize that you may be in a better place than me, and better able to control your ex and how he would use the situation with respect to custody of the kids....just sharing my story!
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