My X has an OM now. Technically I've been told he's "a good friend" but I'm not gullible. The fact she is dating doesn't bother me and I'm not surprised by it.
But OM spends a ton of time with my kids. I've dated a little bit, but I would never introduce someone to my kids right now, not while we are still in the middle of sorting out our D.
I wouldn't even know about OM except my littlest always brings him up, even though I never ask. My older two have clearly been instructed not to mention OM, and will change the subject if my youngest mentions his name. It's really weird. I don't pry, I just say "Oh OK" and move on.
I know this is all ridiculous and I should let it go. I can't control it. But it nags at me. I didn't get a picture of my kids trick or treating while OM and X took them out. It hurts to feel replaced as a dad, not as a husband. Even though I know they only have one dad.
There is one other aspect that really frustrates me about my sitch. My X is controlling and will distort facts to justify what she does. She did this when we were happily married, I just wasn't at the other end of it at the time.
She has tried in many subtle ways to minimize my role with our kids. I really went through h3ll the last 18 months dealing with her threats of withholding the children. I made it out intact, but I know she will continue operating this way. The legal process will end eventually and I'll be left having to deal with her manipulations forever.
Probably some of this has to do with my insecurity about being a good father and my general lack of a support network where I live. Maybe this is something I will start discussing in IC.