Since it makes me puke to have to talk to you, I cant describe to you every bit of bullshit you've handed the kids over the last three years. Howver, since you're just now wondering out loud why it seems like you've messed this all up, let me give you the cliffs notes to your fucked up tale of parenting:
Lying to the kids about why you left in the first place. It wasn't the best idea to tell them that we we fighting too much seeing as they have eyes and ears of their own and never heard a peep.
Changing stories to then to tell them - a 5 and 9 year old - that you just didn't think the marriage was working. Um, I don't even know how to interpret that. How the fuck are they supposed to?
Renting one shit hole after another after you moved out and making sure they didn't get their own rooms or their own things or a feeling of safety and comfort in their new surroundings.
Springing OW and her bratty kids on them without so much as an introductory ice cream cone. The asshole school of thought dictated that it would be best to move into yet another shit hole, have OW live right across the hall and once again lie to the kids that she's nothing but the new neighbor.
Underestimating the OW bitch who desperately wanted to be legitimized and, within a week got tired of the "neighbor" charade and made sure that the kids were shown a picture of you and her kissing. Nice one!
Feeding them fast food on Christmas eve.
Never, and I mean never, calling them on your off days or making an effort to attend their recitals or school functions.
Never, and again, I can't emphasize the never enough here, taking time away from OW and her kids during visitation to spend time with your own fucking kids alone!
Failing miserably at making their birthdays special and, in fact, waiting weeks to celebrate their birthdays for unexplained reasons.
Allowing that whore to pick on them for stupid, inconsequential things and asking her to share your pathetic life even though it's clear that she has no interest in your children.
Having the nerve to ask me if it's bad enough for you to bother to show up in the ER when your kid is there.
Using their rooms in your house as dumping grounds for clothes and papers and refusing to get them anything but a mattress on the floor.
We all have flaws as parents. But, damn dude - you suck at this! Don't tell me you want to fix the damage you've caused - SHOW THEM. Act like they are the most important, precious people in the world and don't let them forget it. You are a worthless, uncaring, unthinking, immature pile of dog shit and you will pay for the ways that you've decided to treat your kids. They will one day treat you the same as you've treated them - as nothing but a bother that you have an obligation to try to love.
Any one of these things would hurt a kid. Your brilliant combination of things has made it clear who ranks number one in the pecking order. If you had the balls to look in a mirror, you'd see exactly who I mean. But you don't. So, expect to wobble through life and miss out on what is the most important job you will ever have and be a critical part of the most important people you will ever meet. Drink your beer, bang your whore and ignore what's really important. You are nothing but a useless bastard and I pray every day that you drop off the face of the Earth and that I am blessed with enough time on earth to make sure you have no bigger hand in your fucked up version of raising them.