... . completely doubting my objectivity here. Was it a gesture of reconciliation, or just more passive-aggressive BPD crap?
Hi Lights
So... . I'll attempt to put myself in your shoes, and the first thing I'd ask myself is:
"Was the NC clearly communicated to both of them? Do they know that I want NC and there's been no change from my end?"
If the answer to that question is YES, then I'd go to:
"Wow they know I want NC and they approach my child, who is still living at home [BTW is this true? I'm guessing], without telling me about it, which is inappropriate and creepy."
That's all I'd need to know, and I'd interpret the flowers in that light -- ie, another aspect of passive-aggressive, or denial (maybe it's an attempt at reconciliation, but a dysfunctional one).
OTOH, if there's a chance that they don't know that you want NC... . it gets more complicated.
Of course, if they both have PDs, then they can conveniently forget things that aren't convenient
for them... . and that would lead to other questions about how often they've shown that kind of behavior in the past, and what your tolerance for that is, and how you dealt with it last time.
Or, in other words, boundaries, boundaries, boundaries.

Hope that's of some help... . feel free to fill in more details... .