Taylor Swift and Calvin Harris
Taylor Swift and Calvin HarrisScreenshot/ Instagram

Calvin Harris and Taylor Swift may have looked totally smitten by each other at Billboard Music Awards on 17 May. But the DJ was seen with another beautiful woman the day before the big night.

After his 2-hour set at Wet Republic in Las Vegas on 16 May, Calvin and a mystery brunette left together in his SUV waiting outside the venue.

"The buxom babe and Calvin were walking super close together and left in the same car. However, Calvin spent the following night with Taylor, showing some major PDA for cameras and loving her up as she collected a handful of Billboard awards," reported OK! Magazine.

Interestingly, Tay too was in Las Vegas on 15 May to perform at the Rock in Rio festival, but she didn't show up at the DJ's pool party gig.

The 'Shake It Off' singer's friends have warned her about Calvin's philandering ways. 

"All of Taylor's friends warned her that Calvin is a player, but she wouldn't listen to them. He's the biggest DJ in the world and spends his time in clubs surrounded by ladies. What's going to stop him from cheating?" a source said.

"After the DJ has been photographed with this other woman, Tay's friends warned her that the EDM star is constantly with babes and saying the dreaded "I told you so," the website reported.

Acting on her friends' advice, Taylor saw the photographs and confronted Calvin about the woman. But Calvin apparently talked his way out of it.

"Calvin is acting like it's no big deal, and Taylor believes him. She's in denial about how serious he's taking their relationship." the source said.

So, will the next Taylor Swift breakup song be about Calvin Harris?