Looks to me like C blows off plans with A (suffragette meeting, perhaps). Promises to make it up but A leaves hurt and upset anyway.
Based on the last few interactions, I'm actually feeling like Celia may be to blame for a potential split. Aurora has been behaving as anyone would under the circumstances. Even Celia knows it was hurtful not to consider her feelings WRT Petra, but here she is again, standing up her pareja... right after saying she would do "whatever it takes" to be there for her... This is how it starts, ladies!
Honestly, Celia, if you're not mature enough...then make room for someone else...