I'm going to tell a guy to leave me alone and cuss him out after he asked me to do one of those stupid Snapchat games.
Why are you so angry?
Because I'm sick of him asking me to play that game over and over.
While it is understandable that you are annoyed at the person trying to get you to play that game repeatedly, it isn't appropriate to cuss him out over it as that is rude and inappropriate behavior. Even though some people may take a while to get a hint, you should always try to be polite when declining someone who is trying to act friendly.
fuck you
If you tell him no and he cant respect it you can block him. That way you don't have to act rude and you wont get the requests anymore. Sounds like a win-win to me.