Dear Sheila,
My parents divorced when I was 3, and I'm 31 now. My dad never forgave my mom for leaving him, and has never been a good father to us. Now that I am an adult, I can see why mom left him. He was not too nice and was controlling. And while she worked full and pt jobs at the same time, he did not pay child support for many years (he owned his own business, so no wages could be garnished). Court was expensive for her, although she did it a few times. On the few occasions we were with him for visits, he would bad mouth her or make smart mouth comments (really inappropriate for children), and I really commend my mom for not doing those things around us. Until a few years we lived very close to him, but I only see him a few times a year if that. It's only at his mother's house (my grandma's) and he always falls asleep on the couch at holidays and I don't even make it a point to say good bye to him when he leaves. One thing is that he paid for my college, but I feel he owed my mom and me that much. He's never made much of an effort to be there for us or anything when it is important. My mom remarried and our stepdad has been such a great dad to us. When my brother played HS and college football, he never went to the games although it was 1 hour drive for him and a six hour drive for my mom and stepdad (they went to all of them!), but when it was senior recog. day and the parents walked the child on the field to be honored, he felt he should be alongside my brother. What a joke. My grandma felt he should be there, too, and that caused an argument.
How I can relate to you is when my son was born 3 years ago, my biological dad all of a sudden started calling and asking how things were going. I had just gotten home from the hospital and was suffering from PPD, so he was the last person I wanted to talk to. I guess he thought he could get a fresh start, but I guess I'm not that forgiving. He's kind of backed off again now, and I'm glad. I realize as an adult that he isn't very responsible. He remarried and has a 10 year old son, and I can tell you I'm very glad my mom left him and he had no part in raising us because we would have been raised very differently, for the worse I feel.
So, your adult children surely realize that he wasn't there for all the important stuff (ball games, graduations, helping them with homework, calming them when they were upset), so they aren't likely going to just jump in and start calling him dad or expect their children to call him grandpa. I'm sure they admire you and their stepdad for raising them and being there for all those things.
I'm sure that isn't an easy issue for your son having returned from overseas. My husband returned from active duty in Iraq after only 9 months away and he had a hard enough time readjusting and suffered from PTSD. So I'm sure that your X trying to come into hte picture isn't helping the matter.
You did all the hard work, so you have every right to feel the way you to. Just talk to your kids or let them come to you and then I bet you'll see that they aren't all of a sudden going to be doing everything with him.