Hi Tanya
I have just read his profile and don't really know what to say. It's hard to comment unless it's happened to you.
It must be very hard to now be able to talk to him about this in person. I can only guess that you must be feeling very betrayed and upset. I think it would hurt that he mentioned he was not only single but had no children.
When does he come home? It is hard to have conversations like that over the phone.
I have had a similar experience with friends of mine. Do you have an email address, I can tell you about it and offer some more advice if you like.
Good on you for focussing on yourself and the kids. Trying to take your mind off it hopefully will help.