I think Parley/Defy Danger comes from AW's Manipulate/Act under fire. In AW, however, you act under fire by using cool, which makes sense as the "fire" is, in my understanding, the second thoughts you have about their promise, that you are distracted by it and such.
In DW, on the other hand, you Defy Danger with DEX, which is not that straightforward. That's why i will try this custom move the next time i play DW:
When you act despite an imminent threat, the DM will tell you what ability is needed to avoid that threat. Roll+that ability.
On a 10+, you do it, no problem.
On a 7-9, you stumble, hesitate, or flinch: the GM will offer you a worse outcome, hard bargain, or ugly choice.
This is actually based on a post by John Harper somewhere, where he says that they use whatever ability for Defy Danger, whatever fits the fictional situation.
So, with this, you can say that when you resist a parley, you Check Wisdom to see whether you are distracted, having second thoughts about their promise or what not.