Calvin Harris kept his cool for awhile as Taylor Swift and Tom Hiddleston embarked on their budding romance -- until now "Hurtful to me at this point that her and her team would go so far out of their way to try and make ME look bad at this stage," Harris wrote on Twitter after Swift's camp chose to make her writing of Harris's hit "This Is What We Came For" public knowledge "I figure if you're happy in your new relationship you should focus on that instead of trying to tear your ex bf down for something to do," Harris later added