We understand that God loves you. I love you. God also loved Hitler, Sadam Hussein, Osama, and Judas Iscariot. Does that mean they weren't immoral? No. I'm sure you've heard the expression "Hate the sin, love the sinner". Well that is what God feels toward all these people (including you and me.) I'm not sinless by any means, and I'm not saying you're the spawn of satan. However, homosexuality is. Lust is. Drunkenness is. Murder is. And the list goes on.
Also, this song is immoral on more than the homosexual level. She is drinking (God doesn't forbid drinking, but He does forbid drunkenness. And she was drunk) and she is cheating on her boyfriend. She could even sing "I kissed another guy and I liked it". But that still wouldn't make it right.
I will declare that I have lusted and I'm sure I will lust on more than one occasion in my lifetime (you can lust at more than just the human body). I know that lusting is immoral and that I am commiting an immoral act when I do so. Why won't you, as a Bible-believing Christian, admit that homosexuality (and bisexuality) is a sin?