Am I?

Are my lips the only ones on your face?
Can anyone ever take my place?
Am I the one your thinking of?
Am I the one you truly love?
Am I the one...your one and only?
Is your love for me true or is it phony?
Will you still be there when times get rough?
Do you need more than love or is that enough?
Are you still the lock...and I'm the key?
If you truly love me,
Come out and show me.