I have a girlfriend but I love somebody else
Is that really true?! What is it about the other woman that you love?
She has the qualities I'm looking for in a woman, she's kind, smart and funny.
If you are interested in someone who is not your partner, it is best to break up with your partner before you pursue the other person. If you don't, you are setting yourself up to cheat on your partner, which would be very painful for her.
It's not her fault that I'm looking for someone different.
You can't just cheat on her though. Either fix your relationship or end it but make sure it's over before you try looking for someone else.