Many Women (and plenty of men too but not relevant here) are addicted to the NRE - new relationship energy. As the passage of time ensures, she begins to realize that the relationship isn’t what she wants - be it hypergamy or just a bad fit.

Here is the AWALT part - branch swinging. Lots of people can’t be alone, so they selfishly hold onto the person for their convenience until they can branch Swing.

This is why so many men correlate showing weakness or vulnerability to getting dumped and cheated on. Men showing weakness is generally frowned upon. Whether it’s based on toxic masculinity or whatever doesn’t matter. Men have internalized that showing weakness is a universally bad thing to do. It’s easy to attribute an action you yourself subconsciously loathe as the cause of killing your partners attraction, with the effect being getting dropped. But it’s not that. It may be a factor in a number of reasons why she was already planning to dump you, or it may not. It’s just that the bitch had not monkey branched yet to the next guy. People like this suck. There’s no excuse for what she did. But the likelihood that she dumped you because you cried over a movie alone is extremely small. And if you read all of the posts here and on RP about Getting cheated on and broken up with they almost all read identically, because on the surface it seems rational for someone which is not continually observant and introspective.

Tl;dr - Women cheating and leaving is not based on a man showing emotional vulnerability one time. She was planning to branch swing all along. That’s the AWALT to observe when you look back at what went wrong w the relationship .