Pleasant Friend posted:

I believe that’s from the House of Cards Arc. Where Tails fights Sonic because Tails’ parents returned from outer space to bring democracy to their new home planet through means of violent revolution, but Sonic sides with the monarchy because he’s screwing the princess. But the "real" reason Tails is pissed off at Sonic is because Sonic was dating Tails’ unrequited love interest, who turned out to be cheating on Sonic with Evil-Sonic anyway.