The more you point out that he's still in communication w/the ow, the more he will be tempted to do so behind your back and yes, heated arguments will continue.
The call may not have meant anything to him, but it meant a lot to the ow. It told her that he still cares about her and her well being. Now, she knows just how to bait him to contact her.
If he truly was working on the marriage, he would cut all contact w/her, especially responding to her calls, text messages, etc. He's still "addicted" to her and will continue to be that way until he stops returning and/or answering her calls.
The drinks may have helped w/him being mean, but I think, he was that way because you caught him doing something that he shouldn't have been doing. He's like a child getting a cookie out of the cookie jar after "mom" has told him no.
I'm sorry things turned a bit "south" last evening, but unless he's completely transparent about all communication w/the ow to you, it's going to be difficult for him to work on the marriage w/you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
