As long as anything in your VM's is against the rules, you shouldn't worry. When you reported him, i checked his messages and infracted him, but, checking yours, I realized you also broke some rules in the meantime. Reporting a conversation where you broke some rules won't save you from getting warned if you require it.
There is no limit, but, if someone is sending you several bad messages, please report the convo as a whole instead of reporting every message once.
And don't fall in his game. That's the only thing where you messed up D;