Trust and being open is important for a relationship.
But Alex and the MC started as FWB, MC was happy to have somebody to bring him back to life, Alex was happy to have somebody she like, reminds her of her dad and she can have some fun with.
She even didn't know he' has some money or have been at his home - that should tell enough about her feelings at the beginning.
That this would grew into a full relationship (either being together if you are on here or the "harem" route, or just as a friend doesn't matter) none of them expected. Or better: Both didn't want to see that this happens.
Still Alex is Alex.
She doesn't want to share her problems with other people, even with Cath. She doesn't want to bother them.
Just think about how she acted when her dad died. Cath had no chance to get through to her.
It takes time for her to understand that it's not a burden for the MC, Cath or Isa if she talks about what she thinks, how she feels.
This has nothing to do with holding something back, it's just Alex being Alex.
With the experience she had suffered with the band, she's doesn't trust people easily. And the next blow: Cath told the MC about what happened.
Give her some time, she is ok and will open up
Similar situation with Isa.
In her job, it's better not to trust people. That's why she connected to Alex and the MC so quickly.
They didn't see her as the model, but as a lady that needed help.
There will be some surprises in her story though.
For the three of them together, it needs some bonding time between the girls.
"Ok, MC, fuck the big tit supermodel" wouldn't work for Alex and Isa "Hey MC, I want to fuck you" isn't working either, doesn't matter if you are with Alex or not.
I hope that explains a few things
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)