What are your thoughts about me marrying my girlfriend, but not acting like a traditional stepdad to her kids.
Why do you want to marry your girlfriend if you don't want to help parent her kids?
She's really great and we make a great couple.
It's nice that you found someone who you enjoy being with, but it doesn't sound like you're ready to marry her. She'll need the support of her husband in parenting her kids. If you're not ready to do that then you're not ready to marry her.
I guess we're not ready to marry, but I would never hurt her.
You can always continue your relationship, however, you should consider what role you will play in her children's lives.