I'm constantly insulting my friend's crush
Why would you insult your friend's crush?
I'm worried about the friendship. He's been crushing on this girl for a while now.
It's not okay to insult other people. You should allow your friend to have affections for others. He might resent you if you put down someone he cares about.
It's not like I'm saying mean thing to the girl to hurt her. I think she enjoys them.
Even if she may like it you should not insult people. Other people see you behaving that way and might not want to be around you.