My ex and I moved in together 3 months into the relationship, admittedly we were both young and childless back then and I kept my flat available until we married but it just felt right. We were together for 10 years, sadly I fell out of love by the third year. I don't think that waiting would have been made any difference.
After the split, I met several guys and eventually one that felt as if I had known him all my life. He was absolutely perfect, great with DS, etc (yeah, he met DS on the same day that he met me and I met his boys, but then we met at a mutual friend's house so I never imagined we were going to end up together).
So... he started staying over very soon, by the 3rd month he had proposed and met my parents (who live thousands of miles away) and his parents travelled all the way from the other end of the planet to meet me. Fantastic, it was like a dream, those 3 months I had the family I always wanted to have. I loved him and adored his children. Then we had a rather stupid little argument and things fizzled out as quickly as they came around. One week everything was perfect, 3 weeks after he was completely gone.
Now after all these years, I can look at the things with a cool head and realise that many of his quirkiness that I found "cute" at the time we were together were actually very strong signs of a very controlling nature. He couldn't bear to be without me, he would miss me so much while... he was at work mmh, he was not interested in meeting with my friends but was happy to organise our outings without consulting me at all, and wouldn't even discuss disagreements e.g. I didn't want to do this or that he had organised (he couldn't imagine he could ever be wrong so why bother talking things through?)
I would tell you to wait, especially because of your children. Picking up yourself up from a potential break up is already difficult but seeing your children heartbroken at loosing a "parental" figure yet another time is what hurts the most.
I cried for his children for months, DS still miss them, I know his children were also very upset about the break up. Him? oh no, he had come out of it completely 2 weeks after we finished.