They don’t want the same thing!
She’s looking to build a castle with someone. He’s looking for a good time.
When you are ready and want a healthy, committed relationship and they tell you they only want something casual or they aren’t ready for a relationship, this is not when you tell yourself, ‘Cool! Let’s see where this goes because there’s sexual chemistry and they have potential.’
Of course there’s sexual chemistry but you want more and they don’t! This is enough for you to see that they are not right for you!
In this scenario, she showed him that she was okay being on-call for him. There was no expectation for him to open his heart for her because he told her he only wants something casual.
As she continued to be available to him, complaining, yet tolerating his randomness and uncertainty about when they would get together next, she felt more and more unloveable, not good enough, like she was just a convenient option, and unimportant in his life.
He is not interested in building a castle with her now, or maybe ever.