Not true, but that's your choice. There are plenty of ways to verify whether or not a wayward spouse is still in contact with OP. My point was simply, either do that, or drop it, because the "middle road" of this issue only drives you AND her crazy.
Of the choices:
1. Assume they are telling the truth -- they are no longer in any sort of meaningful contact or relationship with OP;
2. Assume they are NOT telling the truth, and plan accordingly, until they offer to promise no-contact and full transparency;
3. Assume nothing; verify independently what's going on.
. . . only #2 and #3 are wise, and #1 is just naive and foolish, in my opinion.
Everyone says "I have to trust." Um, why? Why do you "have" to trust someone who's already lied to you, doesn't trust have to be re-earned? If they ARE still in a relationship together (or even if the wayward spouse wants to keep that option open, either as a viable "Plan A" or even a fallback "PLan B" in case your changes aren't for real), isn't it reasonable that they would lie to you about it?
All I'm saying is, either find out independently, or DROP IT, because asking the person themself "are you still with him?" is just crazy. And crazy-making.