Kimmerz, It sounds like he thought he had to provide a justification as to why he was getting a landline, i.e., ow went back to work. I'm glad your girls are telling him to call them. They are sick to death of the text messages and having to respond to them. Your girls are very smart...they just may be the ones that will "control" your xh w/o him even knowing it.
It appears that your D10 is his best bud. I'm sure she just listens as he runs off at the mouth. She'll tell him what she thinks when she's had enough.
As for Christmas, I would think he would tell his daughters about the plans, but then again, he knows that they wouldn't be w/him if they knew about her family being there. Your MIL is very wise in bringing the nicer gifts over to your house. Funny, she knows about that family already and has told you a little bit about them. I'm sure she can't even imagine why her son has hooked up s/this twinkle twat, but she doesn't want to lose him, so she's going over there for Christmas.
Hopefully after the holidays, things will settle down.
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.