When do you call it quits? The affair, the ongoing lies

I recently found out that my husband had a second affair. The first was early in the marriage and before we had kids and with a co- worker. Here we are 10 years later , with kids and he's had another affair with another co- worker. This time he raised the stakes; they travelled away together twice and she continues to work together yet he has complete control of letting her go. Since finding this out the lies have continued. He has maintained a personal and professional relationship with her with 'friendly'text messages, shopping trips, online games, phone calls from the house etc. Everytime I confront him he responds with anger and even near abusive actions. He has redirected mail (credit card statements) and blocked what was once a family online account. He, in one breath claims to want to be with me but then I continue to be slapped with new findings. He says he needs privacy and that after these few months it's unrealistic to expect him to be an open book.
Tonight in fact he said that he was disappointed that I haven't forgiven him yet. He is great to the kids but not to me. Can we stay together for the kids? But Don't I deserve more? He says that it can work this way but in my gut I feel that it's lost. He keeps thinking that my feelings are based on the recent affair but I'd be a fool to forget that this is the second time it's happened. When do you call it quits?