First time poster in this sub. 

I just finished reading "Eggshells" and am currently reading "Splitting."  Opened my eyes.   Been married for 17 years and am currently (1 month) into divorce.  We have a nearly 14-year old.   We had been separated for 1 year but they moved back in the marital home a couple of weeks ago on account of COVID.  My STBX is undiagnosed but certainly exhibits many of the behaviors.  Whether they have BPD or not, it's definitely helped me better understand how to cope and interact.

So about 4 months ago I started dating.  Didn't share with STBX or my son because, well, not their business right now.  With my STBX moving back into the house, they decided to go through my work emails and discovered my dating.  That's been explosive to say the least.  Lots and lots of rage and drama.  Occasional regret, remorse and self doubt but always on a repeating cycle.

The "new" thing that is very difficult to handle is the raw behavior expressed in front of our 14-year old.  The person I'm dating is African American and my STBX is using horrifically racist language and behavior.  Confronting them on this is unhelpful as the attention fuels them and seems like an incentive.  But then ignoring sends mixed signals to my kid as I would normally confront bigotry anywhere.  So I feel stuck (again).  

I'm currently working on getting my SBTX back out of the house (easier said than done).  But I'm curious if the community has any advice in the meantime.

Thanks in advance!