Nic I'm sorry I'm coming in on the tail end of this latest twist in your sitch. You know I understand I have been there. My H wasn't even as considerate as yours! He got engaged to OW in April 06 just 4 months after meeting her. He didn't tell any of us. He waited until the children went to a BBQ in July at his house and D17 noticed that OW was wearing a ring on her left hand and asked him if it was an engagement ring. It was and guess what............ he chose to invite the children round the day before our wedding anniversary (I was away staying with friends) by the time I found out (message on mobile from D17) it was my wedding anniversary. To this day he has never actually told us formally. Compared to mine your H has been a 'saint' on this occassion!
You know where to find me if you want to discuss this further in private.
Me 43 XH 45 M 2.7.88 Divorce 7.10.09 Kids D20,S17 & D15