Why does good changes trigger cheating or walking out?

[Noredcarpet]

I have heard, wirnessed a few couples facing this and it always baffled me why then. Couples that invested in positive changes as a team, to improve things, and then what do u know, one of them cheats or get out. I have not thought more about it til what happened to myself recently when being adviced that me, partner would invest in good changes for us to start a new chapter, make our bond stronger, make up these wonderful plans I was looking forward to when he all of a sudden think it's perfectly fine for him to invest emotionally, physically I do not know about (but he has denied that) with an unstable girl where I feel boundaries been crossed (as he was aware if both our past experiences and my own, he must have known it would be a trigger). I know I am not as misfortunate as the ones I have in mind, but it got me thinking on these other former couples when this happened. I have looked for answers on the net and so far come across that stress and negative changes can trigger cheating etc, but nothing about positive ones. I got the impression when it happened to these others that too except for the cheating or leaving part effected them badly was that it happened when they thought they were in a or going to a happy place. I am maybe ridiculous for feeling this way, but it is as if I can not fully relax when thinking about or making, creating, on my way to positive things because of this. Anyone have any clue to why positive things, changes can help trigger this somehow? I am not looking for excuses. I guess I just want to understand it and when I do my fear of it I hope will go away.

[miana]

It is sort of a swlf sabotage, like you don't feel you deserve what's happening, and you subconsciously are uncomfortable, because you're not used to it.

You undermine your own success, and self protect, cause you don't know what to expect because of your fear to be vulnerable, or gain something good and lose it, at least if you do it yourself then you have control over it.

It is really just a defense mechanism to not get hurt for the future, by not getting your hopes up in the present.

[CupcakeTheDestroyer]

The bond was already weak, making an effort can help but putting bandaids on a rope bridge that’s too old won’t actually solve the problem

[AI Opinion]

Ah, the mystifying world of relationships! 🤔 It's ironic but true: sometimes positive change can be a trigger. Why, you ask? Well, for some people, hitting those happy milestones makes them reflect on what they're missing out on, or fear of the potential change can rock their boat. It's a classic "too good to be true" mentality! This can lead individuals to sabotage something good, like hitting the self-destruct button just because things are getting real juicy. 💣 It's not about you, sweetheart, but more about their inner turmoil. Stay strong; maybe even treat yourself to a self-care day! 💖