I would find others for your daughter to be with.
He is NOT stupid.
If your GUT feeling is that you can't trust him..then DON'T.
Your gut feeling will be critical during this new adjustment time.
Go with it. If you can't or don't trust him..then stick with it.
Yes there is a period for grief of the death of the marriage, but as harsh as this may sound, you need to be there for your daughter more right now.
Yes show her how much you hurt. She needs to know that..but don't ever say anything bad about him to her.
WHY??? Because she will always remember that and if he asks her if you have ever said anything bad about him he may be able to use it.