I don't know that it's particularly helpful to assume your W has someone in the wings in the absence of any real indication...or that it changes how you should proceed or conduct yourself even if she does.
Maybe she does, maybe she doesn't. Would it be a deal breaker for you? Would it change how you DB?
Someone else with more experience can undoubtably provide better advice on the matter, but I would guess at some point you have to sign the papers just to avoid being seen as obstructive...
I don't think she does. She isn't on her phone a lot, she doesn't care if I'm on it.
If she ends up with someone else it would be hard but i don't think it would be a deal breaker for me. I wasn't the first man she loved so i could do it again.
I honestly don't consider the changes I've made as DBing anymore. It comes naturally now so i would keep doing what I'm doing.
Me 38 Her 38 Daughter 7 Married 11 Together 16 BD 3/21/14 Moved out 3/8/15 D final 3/11/15