For all those wanting to get rid of Walter, let's not forget that the narrative is that Bibi is desperate to get as far away from him as possible. The story needs him as one of the driving motivations for the girls/Bibi. Unconsciously I am sure she is thinking depraved sex with Jason is at least her choice and not forced on her like Walter has forced himself.
Angie's motivation seems a bit lacking and I thing it would have been a great idea for Walter to get his hand on Angie too. Being the ultimate bad guy I would not be surprised of him expanding his interests. That way the girls would have a deep bond over the same situation, as opposed now they are just introduced as best friends. That would make Angie's motivation much more understandable. It would also be nice to see why Bibi can't talk about what happened to her mother, why kind of hold Walter has over her. A short dialog and rough/kink sex scene with Walter and Bibi's mother would also show that what he did to Bibi is not an exception. Walter could have forced Bibi to watch, and during sex Walter could humiliate Bibi's mother and get her to say she would agree to a threesome with her daughter. That would make it look like Bibi can't talk to her mother, even if not true.
I also feel the jump from Angie resisting to dropping her panties was a bit too quick at this point. Maybe the lack of any dialog from her during sex is one thing I find missing. I know she says a word or too but it feels like she is a non-character at moments.
One slow-burn option would be Jeson getting Bibi getting Angie high on weed and then "guiding" her to give Jason a BJ. We could have a proper sexy nude/semi-nude photo shoot that would end with girls high and a double BJ. I would wait for sex between Jason and Angie just before the Bahamas trip.
Jason could use that time to train Bibi, she is after all staying at his place now and is fully dependent on him, having no job, no money, no place to say, nothing but dark future is she stays on her own.
Man, from all the depraved ideas here this game could run on for years