Can I spread rumor's around my friend's crush after he started dating my crush.
Why would you spread rumors about this?
Because his crush is a known liar and I won't let her play people just because of her looks.
You shouldn't bugger around with other people's relationship regardless of what you think of anyone's character. You should instead communicate with your friend and let them know personally what you think and allow them to judge for themselves.
I'm literally heart broken and I won't be able to breathe unless I make my friend feel the same way.
It would be best for you to move on to new things in your life. You should put that kind of energy into yourself.