Avoiding or Withdrawing
The first time I had a big fight with my husband (MrS) after I was with my bf (Dude) I found that my attention was 100% on the situation with MrS. I was distraught - I couldn't think about anything other than the fact the MrS was upset. Poor Dude (who lives with us) - at one point I actually told him to "get out" even though our argument had nothing to with him. This was wrong, but thinking about anything except MrS's distress was painfully distractingly to me.
I'm not saying that not talking to you is right, but perhaps he doesn't have the tools to deal with his wife's distress at the loss of her bf . Perhaps he is so focused on consoling and supporting her that he is ignoring his other obligations (i.e. to you). When her situation (grief at the loss of her relationship) settles he may come to you and apologize for his lack.
So, a question - how long has it been? - in terms of your "exploring" a relationship with her husband, since her breakup with her bf, how long had she and bf been "live in" lovers, etc. Is he actually avoiding you or just distracted by his wife's distress? I think these factors would influence your response to his unresponsiveness.
Me: poly bi female, in an "open-but-not-looking" Vee-plus with -
MrS: hetero polyflexible male, live-in husband (23+ yrs)
Dude: hetero poly male, live-in boyfriend (4+ yrs) and MrS's best friend
Lotus: poly bi married female, "it's complicated" relationships with Dude/JaneQ/MrS (1+ years)
+ "others" = FBs, FWBs, lover-friends, platonic G/BFs, boytoys, etc.
My poly blogs here:
The Journey of JaneQSmythe
The Notebook of JaneQSmythe