Fresh from the PDA at the Billboard Music Awards 2015, Calvin Harris is now reported to be cheating on Taylor Swift with a mysterious brunette while performing in Las Vegas.

According to the tabloid Star, as relayed by OK! magazine, Taylor Swift reportedly saw the photograph of Calvin Harris hanging out with a mystery woman in Las Vegas on May 16 and she confronted the DJ about it.

The source told the tabloid of the cheating rumor, "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 added, "All 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?"

OK! magazine also published the photo of Calvin Harris leaving the Wet Republic with the mystery woman as they jumped into his car.

Witnesses claimed that Taylor Swift's boyfriend and the woman "were walking super close together and left in the same car."

Meanwhile, Taylor Swift is now taking the cheating rumors involving boyfriend Calvin Harris as material for her next song.

According to Celebrity Dirty Laundry, the Calvin Harris cheating rumors only gave her the ammunition to continue to reap success in the music industry.

"Swift has been known to date a ton of men and get herself involved with a bunch of relationships, just to get material for her new songs," it said. "Since Taylor Swift was recording and releasing her music, and preparing for her world tour, the superstar did not need any new material."

"Now that Swift is beginning her tour, she will have time on the bus to begin writing her new music, and how can she write music without going through the heartbreak that she and millions of fans seems to love?" the article noted.