I'm leading on a girl who likes me in order to get closer to someone I like. Is that cruel?
It is. How do you know you're leading her on, though?
I know she likes me, but I don't like her
I know you can't force yourself to like someone, but you can stop leading them on. Just be honest with her so things don't get awkward.
That's not my fault. She can't blame me for what is happening.
She can't blame herself for liking you, but she can blame you for lying. Trust me, what you're doing isn't right to anyone involved.