Thanks, to you both. It's certainly enlightening to get other perspectives. I'm glad you pointed out that what he said should be taken positively, rather than negatively. I didn't see it that way. About both the kids and ML. I perceived them negatively.
And, I did "reward" him. After he was gone, yesterday, I sent him a 3 line email that basically said I was happy to see him spending time with the kids and that he was a good father. he didn't say anything about it, but that's OK. I didn't expect him to. It made me feel good to say it, because it's true. When he's good he's good. I sent the email because he had texted me {taking the kids} was hard for him to do too {because I had said it was hard for me} - I also thanked him for sharing this with me. Didn't dwell on it, just the simple thanks (with my intent that maybe it will get him to share more in the future).
As for how I ended up being the only "parent", well his work schedule is grueling. He wasn't here a whole lot...and when he was, lots of times the kids were already asleep when he got home and he would leave before they got up. Can't do something if you're not here to do it; or sleeping - so the onus fell on me. Think about a truck driver only being home on weekends; or a military man gone - that's how it was around here.
Then, when he WAS here, I guess i continued to do things because I felt that he worked hard and so he deserved a break. And home was his break. Or there were things that would need to be done that only he could do - fix the shingles, mow the lawn - yeah, sure I could have done them, I guess. Excuses? I don't know - yet that's the way it was.