With respect to him accepting that way of life - I think BB was probably abused and manipulated by Sarah, I don’t think she suddenly became a monster after meeting Jorge Torres. We all know SB had no issues using the law as a cudgel to deliver more blows on JT, do we really think she wasn’t screwing with Brian in family court, threatening him, attempting to destroy his reputation, harassing him and his family when she didn’t get her way? I think the first taste of control over his own life, finances, household, and parenting came a few months after she was arrested when he realized she’s not coming out, he doesn’t have to worry about her and her behavior anymore.
If he knew anything it could've only helped him to be forthcoming about it. Also, if he knew anything Sarah would’ve held it over his head in order to try to force him into resuming the alimony payments he’s refusing to make while she’s incarcerated. She’s been furious about that for a while (give that letter a read, it’s insane). For all we know she placed the call to Brian that night just so she could say later that she had tried to flee to Brian’s house but couldn’t for whatever reason. She could claim the reason she didn’t call 911 was because the last time she did she was arrested for it. Bada-bing! There’s her excuse for not fleeing and leaving him in the suitcase.