The 32-year-old actress has accused the 34-year-old DJ of being ''petty in the public'' in the aftermath of their split and Lena has therefore named him as her least favourite of the Taylor's ex-boyfriends.
The high-profile pair had a falling out in 2016 when rumours surfaced that Taylor had actually written the lyrics to Calvin's song with Rihanna, 'This Is What You Came For'.
During a game of plead the fifth on 'Watch What Happens Live With Andy Cohen', Lena said: ''I want to do right by her on this question - and I'm also proud, because I haven't pled the fifth on any of these and I think that makes me some kind of champion!
''My least favourite was Calvin Harris, because I felt he was petty in the public and who needs to do that?''
The 'Girls' star also spoke of how ''proud'' she is of Taylor for her recent decision to voice her political opinions.
This follows an Instagram post in which the 'Delicate' hitmaker encouraged her fans to vote.
Taylor, 28 - who has been dating actor Joe Alwyn since 2017 - also revealed she would not be supporting Marsha Blackburn, a Republican member of the US House of Representatives.
She said: ''That was really amazing. I mean, I'm always proud of Taylor. Not only is she an amazing friend to me on a personal level, but she's an amazing friend to lots of people in the world.
''She felt it was time for her to talk about politics - and I never judged her for considering that a private domain - but I think she chose a really, really powerful time to speak out.
''I'm so moved and honoured to be her friend.''
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