Taylor Swift was all smiles while holding Calvin Harris's hand on Thursday night. Just a week after Taylor and Calvin spent time together in Nashville, the pair was spotted showing some sweet PDA in LA. Both rocking all-black outfits, they went to Haim's concert in West Hollywood, where Taylor was spotted sitting in his lap. While Alana, Danielle, and Este Haim are among Taylor's circle of friends, Calvin worked with the sisters for the song "Pray to God." Keep reading to see pictures of Taylor and Calvin's night out, then see the surprising link between Taylor's boyfriends and BFFs.