posting the argument I had tonight with J. open to feedback, and I feel the conclusion is good material on how to revert a beta moment.

executive summary: I slided heavily into beta territory, still got what I asked for, and managed to get out of the mud with little damage

now the facts.

I asked J to go to a trivia night tomorrow in my city. she said she was busy. had to go to dinner with a friend (the friend is a guy. I met him - he is as AFC as it gets, so deeply into friend zone it's not even funny, might even be gay - no worries in that area). I suggested she should flake and she said she could not and did not feel comfortable doing so.
my beta-self got mad at her and after half an hour I texted "off to bed. g'nite."
she understood something was up:

J:
Are u angry at me
Me:
not angry
J:
U are something tho 
Me:
yup
J:
What are you 
Jealous 
Me:
neither
J:
Wanna talk for a minute I don't like going to bed like this I am in bed too 
Me:
ok

the conversation boiled down to "I wish you flaked to come see me" - "I cannot but this does not mean I do not care for you, I will still see you Thursday and Sunday" and so on for five minutes. In the end, we agreed to disagree and just said "bye" to each other.

as soon as we hung up the phone, I suddenly realized that I had been as beta/needy/AFC as it gets.

I called her back five minutes later. She did not pick up the phone. She called back two minutes later.

I said: "I realize I have been rude. And childish. I just missed you."
She said "I have changed plans. I will see my friend on Friday and I will come see you tomorrow."
Me: "I love you"
J: "I love you too. Even if sometimes you're childish. It's good you acknowledge it. It takes you a while, but you realize and you acknowledge it. I appreciate it. Now we can go to bed the proper way"

my lessons learned:
- you can afford to be beta sometimes. but be ready to apologize for it.
- if a girl cares enough, being needy can work once in a long while.

my goals:
- avoid beta moments for at least 2 months from now

_________________
nice guys don't get laid
"It's disrespectful not to bang them when they sleepover." (Hellhound)

You have an awesome girlfriend. Pretty sure most girls would not be as nice towards you for making her change plans just for you. You were wrong but your girl seems mature enough to make up for your behavior.

Apologizing is still risky because you acknowledge you were wrong and she was right. Some girls like to take advantage of this and make you work for it, so when you call she wont pick up or ignore you for a few days.

So praise yourself you have a really nice girlfriend.

_________________
Do not make external things like girls define your happiness or you will live a harsh life. Keep doing what you love and keep improving as a man.

Very true. She rewarded my bad behavior. Rare.
True. I guess my beta-self was looking for validation (show me you care enough to flake on your friend at my whimsical demand). I am glad I got it in spite of being wrong. I would have probably ended up resentful if she had stuck to her plans. And having apologized BEFORE she told me about the plan change, I hopefully avoided resentment on her side. Of course, I will not repeat this pattern of behavior for a very very very very long time.
It is risky, true. It is also a significant power shift (you apologize - you lose any right to complain about the behavior that made you upset in the first place). But I believe recognizing one's mistakes and making amends is more alpha than sticking to a wrong course of action out of sheer stubbornness. So, I think I started the night as badly beta as it gets, but I ended it on a more alpha-ish note (and with my much-desired validation).
I do. And she has earned herself a fair share of reward for her good behavior

_________________
nice guys don't get laid
"It's disrespectful not to bang them when they sleepover." (Hellhound)

Wow, she is clearly very much in to you to have overlooked this, I imagine that you must be well established with her for this not to be a problem.

Especially as you rang her back after the falling out you did, very risky indeed.

A lot of people make this mistake in a lot things in life, they are working on something, they mess up and rather than walk away and having some time out they try to fix it there and then, and more often than not the mistake turns in to something a lot worse.

This girl sounds great, but like you say good thing you have realised the beta mannerisms that were coming across.

I guess so. She was not happy about the whole thing, of course. Neither am I. But she clearly accommodated my demand. And was happy enough of my apology not to push the issue any further.
I have this positive detachment approach for work stuff. But it's harder for me with significant others. Plus, unlike my exGF who made me crazy angry and fed on the drama, J is able to defuse my bad moments. This makes me want to come to a (positive) closure, instead of letting the anger boil.
Sometimes people make stupid shit. In a relationship, you have a certain margin before it becomes a critical issue. Fortunately. I learnt this by looking at me with my ex. Before her drama and shit became too much, I got mad at her and then forgave her for quite a while. The issue is not the shit itself. It's when your significant other does not improve. My ex never improved. I try to improve.

_________________
nice guys don't get laid
"It's disrespectful not to bang them when they sleepover." (Hellhound)