Introducing new gf too fast - regrets

I messed up. My girlfriend moved in with me after like 4 months of dating and now my kids are confused about boundaries and relationships. My 7yo keeps asking why she sleeps in my room and if they're going to get married. I didn't think this through and now my ex is using it as ammunition saying I'm not being a stable influence.

She's probably right. Girlfriend's moving out next month. Just wanted to put this out there so someone else doesn't make the same mistake.