If you want to wait until after the Retro weekend to see what the weekend brings then tell him that - it's not unreasonable.
If you really think he is coming back because of your children or because he no longer wants OP, (or OP doesn't want him), as opposed to coming back because he wants to be with you, do you really want him back. Don't let yourself settle for thinking you are a default option. You are not second best.
You owe it to yourself to find out whether you want your M or not but only do what you feel is right for you.
My gut tells that if you take him back too early then your door is going to start revoloving again. But hey, I don't know him and could be completely wrong. The decision is a weighty one. I would factor your children into it and think what would harm / help them most as well.
Sorry I'm not more help.
Saffie
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength