I agree with the others about your need for therapy. I am not going to call you names and judge you. You asked for help, not to be abused.
I have to say this and excuse me if I sound like I am standing on a soap box...
People like the op are asking a question, asking for help. Who are we to judge him, call him names? He is admitting his failures, admitting he is wrong. It's pretty damn redundant to be saying all the things he is saying himself. Some of the holier than thou attitudes on this site piss me off because questions like these are not going to be written, people are not going to get advice they sorely need because of judgemental bitter people.
So perhaps, if you have nothing constructive to say, without throwing a couple jabs in there, you should just sail past the posts.
You have a good point - though I have to say I got a bit pissed off reading the OP. He does recognise that he's being unreasonable but he still brushes it off as if it is not the biggest deal.
To HungCountryBoy - please try to recognise that your wife probably has some serious issues surrounding your behaviour. If sometimes she goes a bit 'crazy' like she did at your birthday celebration just try to give her the benefit of the doubt. She only 'acting out' because your behaviour confuses and upsets her. Think about it - you want to keep her all to yourself, you want her to be the faithful wife, the perfect mother, a thoughtful and mindful companion who puts your needs first and also a dirty whore in the bedroom whenever you want. It must have occured to you that she wants certain things of you. She maybe be reconciled with your cheating but she might need to be much more discreet about it or give her more freedom in other areas. You can't own her - if you try you will lose her.
I have seen couples where one partner is compelled to have multiple partners - the only cases where that works at all and doesn't end in ugly bitterness is where the partner who 'needs' to 'cheat' allows the other partner as much freedom as he/she needs to take. Whether this freedom means a boyfriend for your wife, or you staying home with your child every second weekend while your wife goes white water canoeing is immaterial. She is a grown up too, with wants, needs, desires, frustrations - just the same as you. At the moment, by your own admission, you are taking and she is giving with the odd 'slip up' like happened on your birthday. It was minor - I'm sorry it upset you so much but really it shouldn't have. Forgive her, she forgives you so much every single day.
You owe it to your child to do this. The impression you are giving your child of what a relationship should be is unreasonable and unhealthy. Your child needs to see you and your wife respecting each other - monogamy is not essential to that, but evening out the give and take is. Children know when mom and dad are unhappy with each other - even very young children.
You won't get much sympathy here, but that is somewhat unfair as in reality if you are what you say, you are going to get a lot of women wanting a piece of the action and they won't give a shit about your wife and kid let alone their husbands and kids. People won't like me saying that, but I can name names. Not that I will of course.
This is indeed true. I don't believe the OP needs sympathy though. I think he needs to wake up to the fact that his wife is unlikely to put up with the current situation for long, and if she does she is not going to be a pleasant person to be around as her frustrations will work themselves out in one way or another. I think by even posting this he is realising there is an issue - he seems also to know that he is the issue, the next step is realising there is no quick fix.
From a polyamorous pov you also have to get over your jealousy issue. Sounds to me that your partner is going to enjoy sex with smaller guys more than with you. Potentially, if you understand each other's needs, yet need each others other relationship bnefits, then you may have something going within an open relationship, though you have some big issues there.
People tend to think that men can sow their wild oats and then settle down, but the truth is that some guys don't and/or can't.
I agree - his wife needs something that is completely hers. That does not have to be a sexual relationship but her husband does not get to choose that. If he can't bear to give her that freedom but still wants his own then I believe separating is the only healthy option.