Hello, I am Rafael. Thanks for asking your question - I'm here to support you.
This is a tough situation to find yourself in, having to choose between your life partner and your daughter. It should never been that way once these are two different relationships which should not conflict one with the other.
Your partner has been living with you since she was 8, then there is no way for him as an adult and life partner to justify not having the time, means, conditions and responsibility to build a healthy relationship with a child based on mutual respect, empathy, understanding and support, areal parent-child relationship.