My DH never takes the bait because he could care less about BM but she and now SD12 both try to setup competitions between him and the new stepdad (who we've never met, just said hi in passing, my husband feels sorry for him). 

My DH and I are very open with each other and agree not to let kids or our families triangulate or play us off one another. 

DH usually takes SD12back to school shopping for a new lunchbox, backpack, all that. This year she told him she did all that with her stepdad. Ok DH was a little put off but fine if stepdad wants to pay for it he can go ahead.

For her past birthday and Christmas she has given a list of wants but when DH presses about the usual things he gets her SD says her stepdad already got them. Fine again, stepdad can buy your new Nikes. 

Then there's BM. DH was having trouble connecting with preteen angsty SD so BM told him she'd have stepdad give her a talk about it. Um ok, why not just put the kid on the phone? Most attempts to talk to BM about SD turn into her just talking about her new husband.

BM also made a huge deal of hiding her fiance (who she was dating long before my DH met me) and hiding her new address, basically she behaved like my DH was dangerous and violent and going to track them down. Again he could care less. She makes sure her husband is never around during pickup or dropoff. Maybe he is the jealous one?

It's pathetic, BM has a history of wanting to be chased and trying to cause jealousy for her self esteem. Since DH won't take the bait she moved on to trying to make DH chase SD by setting up these unneeded barriers and false rivals. She acts like it's a problem SD won't talk to DH (or anyone lately, she's very withdrawn) but then acts like it's a total mystery of how to get her to interact. I dunno handher the phone? Actually allow visitation rather than letting SD opt out. Ugh