Infidelity Support Group
Any relationship in which one partner engages willfully in sexual relations with another outside of the partnership is considered to have experienced infidelity. This breach of trust is often traumatizing for the faithful partner as well as the relationship, and support is often needed to heal emotionally and to decide whether or not the relationship should continue after...

Can you give us a little background..... how long married, kids, etc?
Cheaters lie, so don't believe him when he says he wouldn't have met up with any of them (yes, there is probably more than one woman).
And what does he mean he wouldn't have met up with that woman, when you said he knows her already???
It takes a lot to get past this, but it can be done. Maybe you could give us a little more background details on this whole situation so we can better help you.