Your instinct always was spot on Solo, you just have to trust it!
WWIFN, who cares what BB thinks, WE all know she is doing it for a desperate attempt to look good and hang onto her maaan (vom) and SHE knows this is why she is really doing it.
If not, she would never have freaked out at the amount of DC time he had planned initially. the photos of the DC only days after he had left his family.
I'd be inclined to say something like he might be stupid enough to fall for her BS, but that I wasn't and will not accept inappropriate behaviour/gifts/people in my DC life.
I wouldn't give a shit if that made me look bitter/unreasonable or whatever, her opinion and indeed his mean nothing to me, as they are neither people of any great moral standing nor people I would go out of my way to know.
I might also go on to give him a flea in his ear for even bringing her into any kind of discussion with me, as I don't want to know anything about her, nor his relationship with her. She is HIS problem, and HE is hers, only the DC are of my concern now.
Oh yes I would be cementing in those boundaries, putting up clear signage too.