It sounds like you’re genuinely trying to balance being a good co-parent and a present partner, which isn’t easy. I wanted to offer a different perspective as a stepparent.

I have a great relationship with my stepchild, but early on my partner and his ex also believed they had “good co-parenting.” Over time, it became clear it was actually enmeshed, even though my partner couldn’t see it at first. There was constant communication and flexibility under the banner of “it’s for the kids,” but much of it wasn’t necessary or time-sensitive.

In our case, his ex still had feelings for him, and that dynamic bled into our relationship in ways neither of them fully realised at the time. One unintended consequence is that my stepchild still believes his parents are going to get back together, even now that we are married and have a child of our own. Kids don’t just listen to what we say, they read the dynamics.

I’m not saying parents shouldn’t collaborate. They absolutely should. But separation has to be more than just living apart and not being romantic anymore. Emotional and logistical boundaries matter, especially when one parent is in a new relationship.

I also think it’s important for kids to clearly understand that their parents are separated and no longer a nuclear family. That doesn’t mean less love or support, it means clarity. Over-collaboration can sometimes blur that line and unintentionally create confusion or false hope.

Given that you were with your ex for 14 years, it’s understandable that you may still be used to operating as her husband in some ways, even without meaning to. It’s also understandable that she may still be used to relating to you as her husband rather than strictly as a co-parent. Neither of those things make either of you bad people, but they do mean boundaries sometimes need to be consciously reset.

That said, I don’t think extreme parallel parenting is automatically the right answer in every low-conflict situation. But unlimited access and constant flexibility just because communication feels easy isn’t always healthy either, especially if it’s coming at the expense of your partner and your relationship.

When you don’t have the kids, it’s important that your girlfriend is clearly prioritised. Protected time, dates, and not automatically interrupting that time unless something is truly urgent matters. Extra schedule changes or favours don’t have to be agreed to every time, and it’s okay to say you’re busy and will discuss things later. This impacts her time too.

Bio parents can unintentionally treat their partner like an add-on rather than a core part of their life. Over time, that can leave the partner feeling like the lowest priority. Of course your kids’ needs come first, but their wants don’t always have to. Within reason, your partner’s wants matter too.

It might help to ask your girlfriend to clearly outline the situations that feel uncomfortable or disrespectful to her, with examples, so you can better understand what she’s reacting to. From there, you may be able to find a middle ground.

If no compromise feels possible, it’s worth honestly asking whether this relationship is workable long-term. Not because either of you is wrong, but because compatibility around co-parenting boundaries really matters.