Been with my DP for years and I've never had any contact with the ex. She has never probed that deeply into in our relationship besides snooping on DP via social media, never shown any interest in the fact that we live together, that her child stays with us for long periods of time at her request (it's my house) etc.
Then when she found out we were expecting a child, she began to ask 101 questions. Wanted to have a 'meeting' with DP to discuss me, my other DC's, where we lived and a bunch of other things that were suddenly concerning her. DP refused as she is usually evasive and secretive about her own life, even at the expense of co parenting their child successfully.
It made me wonder how normal it is in a step-family set up for the step-parent and ex to have any contact? Half of her issues would be resolved if she met or spoke to me in person, it's something I would be willing to do, but not in a forced way.